View LT1963AEFE_4281274.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

LT1963A Series 1.5A, Low Noise, Fast Transient Response LDO Regulators FEATURES
n n n n n n n n n n n n n n n n
DESCRIPTION
The LT (R)1963A series are low dropout regulators optimized for fast transient response. The devices are capable of supplying 1.5A of output current with a dropout voltage of 340mV. Operating quiescent current is 1mA, dropping to < 1A in shutdown. Quiescent current is well controlled; it does not rise in dropout as it does with many other regulators. In addition to fast transient response, the LT1963A regulators have very low output noise which makes them ideal for sensitive RF supply applications. Output voltage range is from 1.21V to 20V. The LT1963A regulators are stable with output capacitors as low as 10F. Internal protection circuitry includes reverse battery protection, current limiting, thermal limiting and reverse current protection. The devices are available in fixed output voltages of 1.5V, 1.8V, 2.5V, 3.3V and as an adjustable device with a 1.21V reference voltage. The LT1963A regulators are available in 5-lead TO-220, DD, 3-lead SOT-223, 8-lead SO and 16-lead TSSOP packages.
, LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6118263, 6144250. *See Applications Information Section.
Optimized for Fast Transient Response Output Current: 1.5A Dropout Voltage: 340mV Low Noise: 40VRMS (10Hz to 100kHz) 1mA Quiescent Current No Protection Diodes Needed Controlled Quiescent Current in Dropout Fixed Output Voltages: 1.5V, 1.8V, 2.5V, 3.3V Adjustable Output from 1.21V to 20V < 1A Quiescent Current in Shutdown Stable with 10F Output Capacitor* Stable with Ceramic Capacitors* Reverse Battery Protection No Reverse Current Thermal Limiting 5-Lead TO-220, DD, 3-Lead SOT-223 and 8-Lead SO Packages
APPLICATIONS
n n
3.3V to 2.5V Logic Power Supplies Post Regulator for Switching Supplies
TYPICAL APPLICATION
Dropout Voltage 3.3V to 2.5V Regulator
DROPOUT VOLTAGE (mV) IN 10F* OUT 2.5V 1.5A 10F*
400 350
+
VIN > 3V
+
300 250 200 150 100 50 0 0 0.2 0.4 0.6 0.8 1.0 1.2 OUTPUT CURRENT (A) 1.4 1.6
1963A TA02
LT1963A-2.5 SHDN SENSE
GND
1963A TA01
*TANTALUM, CERAMIC OR ALUMINUM ELECTROLYTIC
1963afd
1
LT1963A Series ABSOLUTE MAXIMUM RATINGS
(Note 1)
IN Pin Voltage ........................................................ 20V OUT Pin Voltage ......................................................20V Input to Output Differential Voltage (Note 2) ...........20V SENSE Pin Voltage ............................................... 20V ADJ Pin Voltage ...................................................... 7V SHDN Pin Voltage ................................................. 20V Output Short-Circuit Duration ........................ Indefinite
Operating Junction Temperature Range (Note 3) LT1963AE...........................................- 40C to 125C LT1963AI............................................- 40C to 125C LT1963AMP .......................................- 55C to 125C Storage Temperature Range...................- 65C to 150C Lead Temperature (Soldering, 10 sec) .................. 300C
PIN CONFIGURATION
TOP VIEW GND NC FRONT VIEW 5 4 TAB IS GND 3 2 1 Q PACKAGE 5-LEAD PLASTIC DD SENSE/ADJ* OUT GND IN SHDN TAB IS GND FRONT VIEW 5 4 3 2 1 T PACKAGE 5-LEAD PLASTIC TO-220 SENSE/ ADJ* OUT GND IN SHDN OUT OUT OUT SENSE/ADJ* GND GND 1 2 3 4 5 6 7 8 17 16 GND 15 NC 14 IN 13 IN 12 IN 11 NC 10 SHDN 9 GND
*PIN 5 = SENSE FOR LT1963A-1.5/LT1963A-1.8/ LT1963A-2.5/LT1963A-3.3 = ADJ FOR LT1963A TJMAX = 150C, JA = 30C/ W
*PIN 5 = SENSE FOR LT1963A-1.5/LT1963A-1.8/ LT1963A-2.5/LT1963A-3.3 = ADJ FOR LT1963A TJMAX = 150C, JA = 50C/ W
FE PACKAGE 16-LEAD PLASTIC TSSOP EXPOSED PAD (PIN 17) IS GND. MUST BE SOLDERED TO THE PCB.
*PIN 6 = SENSE FOR LT1963A-1.5/LT1963A-1.8/ LT1963A-2.5/LT1963A-3.3 = ADJ FOR LT1963A TJMAX = 150C, JA = 38C/ W
FRONT VIEW 3 TAB IS GND 2 1 OUT GND IN OUT 1 SENSE/ADJ* 2 GND 3 NC 4
TOP VIEW 8 7 6 5 IN GND GND SHDN
ST PACKAGE 3-LEAD PLASTIC SOT-223
S8 PACKAGE 8-LEAD PLASTIC SO
TJMAX = 150C, JA = 50C/ W
*PIN 2 = SENSE FOR LT1963A-1.5/LT1963A-1.8/ LT1963A-2.5/LT1963A-3.3 = ADJ FOR LT1963A TJMAX = 150C, JA = 70C/ W
1963afd
2
LT1963A Series ORDER INFORMATION
LEAD FREE FINISH LT1963AEQ#PBF LT1963AIQ#PBF LT1963AMPQ#PBF LT1963AEQ-1.5#PBF LT1963AEQ-1.8#PBF LT1963AEQ-2.5#PBF LT1963AEQ-3.3#PBF LT1963AET#PBF LT1963AIT#PBF LT1963AET-1.5#PBF LT1963AET-1.8#PBF LT1963AET-2.5#PBF LT1963AET-3.3#PBF LT1963AEFE#PBF LT1963AIFE#PBF LT1963AEFE-1.5#PBF LT1963AEFE-1.8#PBF LT1963AEFE-2.5#PBF LT1963AEFE-3.3#PBF LT1963AEST-1.5#PBF LT1963AEST-1.8#PBF LT1963AEST-2.5#PBF LT1963AEST-3.3#PBF LT1963AES8#PBF LT1963AIS8#PBF LT1963AMPS8#PBF LT1963AES8-1.5#PBF LT1963AES8-1.8#PBF LT1963AES8-2.5#PBF LT1963AES8-3.3#PBF LEAD BASED FINISH LT1963AEQ LT1963AIQ LT1963AMPQ LT1963AEQ-1.5 LT1963AEQ-1.8 LT1963AEQ-2.5 LT1963AEQ-3.3 LT1963AET LT1963AIT TAPE AND REEL LT1963AEQ#TRPBF LT1963AIQ#TRPBF LT1963AMPQ#TRPBF LT1963AEQ-1.5#TRPBF LT1963AEQ-1.8#TRPBF LT1963AEQ-2.5#TRPBF LT1963AEQ-3.3#TRPBF LT1963AET#TRPBF LT1963AIT#TRPBF LT1963AET-1.5#TRPBF LT1963AET-1.8#TRPBF LT1963AET-2.5#TRPBF LT1963AET-3.3#TRPBF LT1963AEFE#TRPBF LT1963AIFE#TRPBF LT1963AEFE-1.5#TRPBF LT1963AEFE-1.8#TRPBF LT1963AEFE-2.5#TRPBF LT1963AEFE-3.3#TRPBF LT1963AEST-1.5#TRPBF LT1963AEST-1.8#TRPBF LT1963AEST-2.5#TRPBF LT1963AEST-3.3#TRPBF LT1963AES8#TRPBF LT1963AIS8#TRPBF LT1963AMPS8#TRPBF LT1963AES8-1.5#TRPBF LT1963AES8-1.8#TRPBF LT1963AES8-2.5#TRPBF LT1963AES8-3.3#TRPBF TAPE AND REEL LT1963AEQ#TR LT1963AIQ#TR LT1963AMPQ#TR LT1963AEQ-1.5#TR LT1963AEQ-1.8#TR LT1963AEQ-2.5#TR LT1963AEQ-3.3#TR LT1963AET#TR LT1963AIT#TR PART MARKING* LT1963AEQ LT1963AIQ LT1963AMPQ LT1963AEQ-1.5 LT1963AEQ-1.8 LT1963AEQ-2.5 LT1963AEQ-3.3 LT1963AET LT1963AIT LT1963AET-1.5 LT1963AET-1.8 LT1963AET-2.5 LT1963AET-3.3 1963AEFE 1963AIFE 1963AEFE15 1963AEFE18 1963AEFE25 1963AEFE33 963A15 963A18 963A25 963A33 1963A 1963A 963AMP 963A15 963A18 963A25 963A33 PART MARKING* LT1963AEQ LT1963AIQ LT1963AMPQ LT1963AEQ-1.5 LT1963AEQ-1.8 LT1963AEQ-2.5 LT1963AEQ-3.3 LT1963AET LT1963AIT PACKAGE DESCRIPTION 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic TO-220 5-Lead Plastic TO-220 5-Lead Plastic TO-220 5-Lead Plastic TO-220 5-Lead Plastic TO-220 5-Lead Plastic TO-220 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 3-Lead Plastic SOT-223 3-Lead Plastic SOT-223 3-Lead Plastic SOT-223 3-Lead Plastic SOT-223 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO PACKAGE DESCRIPTION 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic DD-PAK 5-Lead Plastic TO-220 5-Lead Plastic TO-220 TEMPERATURE RANGE -40C to 125C -40C to 125C -55C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -55C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C TEMPERATURE RANGE -40C to 125C -40C to 125C -55C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C
1963afd
3
LT1963A Series ORDER INFORMATION
LEAD BASED FINISH LT1963AET-1.5 LT1963AET-1.8 LT1963AET-2.5 LT1963AET-3.3 LT1963AEFE LT1963AIFE LT1963AEFE-1.5 LT1963AEFE-1.8 LT1963AEFE-2.5 LT1963AEFE-3.3 LT1963AEST-1.5 LT1963AEST-1.8 LT1963AEST-2.5 LT1963AEST-3.3 LT1963AES8 LT1963AIS8 LT1963AMPS8 LT1963AES8-1.5 LT1963AES8-1.8 LT1963AES8-2.5 LT1963AES8-3.3 TAPE AND REEL LT1963AET-1.5#TR LT1963AET-1.8#TR LT1963AET-2.5#TR LT1963AET-3.3#TR LT1963AEFE#TR LT1963AIFE#TR LT1963AEFE-1.5#TR LT1963AEFE-1.8#TR LT1963AEFE-2.5#TR LT1963AEFE-3.3#TR LT1963AEST-1.5#TR LT1963AEST-1.8#TR LT1963AEST-2.5#TR LT1963AEST-3.3#TR LT1963AES8#TR LT1963AIS8#TR LT1963AMPS8#TR LT1963AES8-1.5#TR LT1963AES8-1.8#TR LT1963AES8-2.5#TR LT1963AES8-3.3#TR PART MARKING* LT1963AET-1.5 LT1963AET-1.8 LT1963AET-2.5 LT1963AET-3.3 1963AEFE 1963AIFE 1963AEFE15 1963AEFE18 1963AEFE25 1963AEFE33 963A15 963A18 963A25 963A33 1963A 1963A 963AMP 963A15 963A18 963A25 963A33 PACKAGE DESCRIPTION 5-Lead Plastic TO-220 5-Lead Plastic TO-220 5-Lead Plastic TO-220 5-Lead Plastic TO-220 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 16-Lead Plastic TSSOP 3-Lead Plastic SOT-223 3-Lead Plastic SOT-223 3-Lead Plastic SOT-223 3-Lead Plastic SOT-223 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO TEMPERATURE RANGE -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C -55C to 125C -40C to 125C -40C to 125C -40C to 125C -40C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
1963afd
4
LT1963A Series ELECTRICAL CHARACTERISTICS
PARAMETER Minimum Input Voltage (Notes 4,12) Regulated Output Voltage (Note 5) CONDITIONS ILOAD = 0.5A ILOAD = 1.5A LT1963A-1.5 LT1963A-1.8 LT1963A-2.5 LT1963A-3.3 ADJ Pin Voltage (Notes 4, 5) Line Regulation LT1963A LT1963A-1.5 LT1963A-1.8 LT1963A-2.5 LT1963A-3.3 LT1963A (Note 4) LT1963A-1.5 LT1963A-1.8 LT1963A-2.5 LT1963A-3.3 LT1963A (Note 4) Dropout Voltage VIN = VOUT(NOMINAL) (Notes 6, 7, 12) ILOAD = 1mA ILOAD = 1mA ILOAD = 100mA ILOAD = 100mA ILOAD = 500mA ILOAD = 500mA ILOAD = 1.5A ILOAD = 1.5A GND Pin Current VIN = VOUT(NOMINAL) + 1V (Notes 6, 8) ILOAD = 0mA ILOAD = 1mA ILOAD = 100mA ILOAD = 500mA ILOAD = 1.5A COUT = 10F, ILOAD = 1.5A, BW = 10Hz to 100kHz (Notes 4, 9) VOUT = Off to On VOUT = On to Off VSHDN = 0V VSHDN = 20V VIN = 6V, VSHDN = 0V
l
The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 3)
MIN TYP 1.9 2.1 1.477 1.447 1.773 1.737 2.462 2.412 3.250 3.200 1.192 1.174 1.500 1.500 1.800 1.800 2.500 2.500 3.300 3.300 1.210 1.210 2.0 2.5 3.0 3.5 1.5 2 2 2.5 3 2 0.02 0.10 0.19 0.34 1.0 1.1 3.8 15 80 40 3 0.25 0.90 0.75 0.01 3 0.01 10 2 1 30 1 MAX 2.5 1.523 1.545 1.827 1.854 2.538 2.575 3.350 3.400 1.228 1.246 6 7 10 10 5 9 18 10 20 15 30 20 35 8 15 0.06 0.10 0.17 0.22 0.27 0.35 0.45 0.55 1.5 1.6 5.5 25 120 UNITS V V V V V V V V V V V V mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV V V V V V V V V mA mA mA mA mA VRMS A V V A A A
VIN = 2.21V, ILOAD = 1mA 2.5V < VIN < 20V, 1mA < ILOAD < 1.5A VIN = 2.3V, ILOAD = 1mA 2.8V < VIN < 20V, 1mA < ILOAD < 1.5A VIN = 3V, ILOAD = 1mA 3.5V < VIN < 20V, 1mA < ILOAD < 1.5A VIN = 3.8V, ILOAD = 1mA 4.3V < VIN < 20V, 1mA < ILOAD < 1.5A VIN = 2.21V, ILOAD = 1mA 2.5V < VIN < 20V, 1mA < ILOAD < 1.5A VIN = 2.21V to 20V, ILOAD = 1mA VIN = 2.3V to 20V, ILOAD = 1mA VIN = 3V to 20V, ILOAD = 1mA VIN = 3.8V to 20V, ILOAD = 1mA VIN = 2.21V to 20V, ILOAD = 1mA VIN = 2.5V, ILOAD = 1mA to 1.5A VIN = 2.5V, ILOAD = 1mA to 1.5A VIN = 2.8V, ILOAD = 1mA to 1.5A VIN = 2.8V, ILOAD = 1mA to 1.5A VIN = 3.5V, ILOAD = 1mA to 1.5A VIN = 3.5V, ILOAD = 1mA to 1.5A VIN = 4.3V, ILOAD = 1mA to 1.5A VIN = 4.3V, ILOAD = 1mA to 1.5A VIN = 2.5V, ILOAD = 1mA to 1.5A VIN = 2.5V, ILOAD = 1mA to 1.5A
l l l l l l l l l l
Load Regulation
Output Voltage Noise ADJ Pin Bias Current Shutdown Threshold SHDN Pin Current (Note 10) Quiescent Current in Shutdown
1963afd
5
LT1963A Series ELECTRICAL CHARACTERISTICS
PARAMETER Ripple Rejection Current Limit Input Reverse Leakage Current (Note 13) Reverse Output Current (Note 11) CONDITIONS VIN - VOUT = 1.5V (Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 0.75A VIN = 7V, VOUT = 0V VIN = VOUT(NOMINAL) + 1V, VOUT = - 0.1V Q, T, S8 Packages ST Package LT1963A-1.5 LT1963A-1.8 LT1963A-2.5 LT1963A-3.3 LT1963A (Note 4) VIN = -20V, VOUT = 0 VIN = -20V, VOUT = 0 VOUT = 1.5V, VIN < 1.5V VOUT = 1.8V, VIN < 1.8V VOUT = 2.5V, VIN < 2.5V VOUT = 3.3V, VIN < 3.3V VOUT = 1.21V, VIN < 1.21V

The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 3)
MIN 55 TYP 63 2 1.6 1 2 600 600 600 600 300 1200 1200 1200 1200 600 MAX UNITS dB A A mA mA A A A A A
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: Absolute maximum input to output differential voltage can not be achieved with all combinations of rated IN pin and OUT pin voltages. With the IN pin at 20V, the OUT pin may not be pulled below 0V. The total measured voltage from IN to OUT can not exceed 20V. Note 3: The LT1963A regulators are tested and specified under pulse load conditions such that TJ TA. The LT1963AE is 100% tested at TA = 25C. Performance at -40C and 125C is assured by design, characterization and correlation with statistical process controls. The LT1963AI is guaranteed over the full -40C to 125C operating junction temperature range. The LT1963AMP is 100% tested and guaranteed over the -55C to 125C operating junction temperature range. Note 4: The LT1963A (adjustable version) is tested and specified for these conditions with the ADJ pin connected to the OUT pin. Note 5: Operating conditions are limited by maximum junction temperature. The regulated output voltage specification will not apply for all possible combinations of input voltage and output current. When operating at maximum input voltage, the output current range must be limited. When operating at maximum output current, the input voltage range must be limited.
Note 6: To satisfy requirements for minimum input voltage, the LT1963A (adjustable version) is tested and specified for these conditions with an external resistor divider (two 4.12k resistors) for an output voltage of 2.4V. The external resistor divider will add a 300A DC load on the output. Note 7: Dropout voltage is the minimum input to output voltage differential needed to maintain regulation at a specified output current. In dropout, the output voltage will be equal to: VIN - VDROPOUT. Note 8: GND pin current is tested with VIN = VOUT(NOMINAL) + 1V and a current source load. The GND pin current will decrease at higher input voltages. Note 9: ADJ pin bias current flows into the ADJ pin. Note 10: SHDN pin current flows into the SHDN pin. Note 11: Reverse output current is tested with the IN pin grounded and the OUT pin forced to the rated output voltage. This current flows into the OUT pin and out the GND pin. Note 12: For the LT1963A, LT1963A-1.5 and LT1963A-1.8 dropout voltage will be limited by the minimum input voltage specification under some output voltage/load conditions. Note 13: For the ST package, the input reverse leakage current increases due to the additional reverse leakage current for the SHDN pin, which is tied internally to the IN pin.
1963afd
6
LT1963A Series TYPICAL PERFORMANCE CHARACTERISTICS
Typical Dropout Voltage
500 450 400
Guaranteed Dropout Voltage
600
Dropout Voltage
500 450
GUARANTEED DROPOUT VOLTAGE (mV)
= TEST POINTS
500
350 300 250 200 150 100 50 0 0 0.2
DROPOUT VOLTAGE (mV)
DROPOUT VOLTAGE (mV)
TJ 125C 400 TJ 25C 300 200 100 0
400 350 300 250 200 150 100 50 IL = 100mA IL = 1mA -25 50 25 0 75 TEMPERATURE (C) 100 125 IL = 0.5A IL = 1.5A
TJ = 125C
TJ = 25C
0.4 0.6 0.8 1.0 1.2 OUTPUT CURRENT (A)
1.4
1.6
0
0.2
0.4 0.6 0.8 1.0 1.2 OUTPUT CURRENT (A)
1.4
1.6
0 -50
1963A G01
1963A G02
1963A G03
Quiescent Current
1.4 1.2
QUIESCENT CURRENT (mA)
LT1963A-1.5 Output Voltage
1.54 IL = 1mA
1.84
LT1963A-1.8 Output Voltage
IL = 1mA 1.83
OUTPUT VOLTAGE (V)
LT1963A-1.5/1.8/-2.5/-3.3
OUTPUT VOLTAGE (V)
1.53 1.52 1.51 1.50 1.49 1.48 1.47
100 125
1.0 0.8 0.6 0.4 0.2 VIN = 6V RL = , IL = 0 VSHDN = VIN 50 25 75 0 TEMPERATURE (C) LT1963A
1.82 1.81 1.80 1.79 1.78 1.77
0 -50 -25
1.46 -50 -25
0
75 50 25 TEMPERATURE (C)
100
125
1.76 -50
-25
0
25
50
75
100
125
TEMPERATURE (C)
1963A G40
1963A G05
1963A G04
LT1963A-2.5 Output Voltage
2.58 IL = 1mA 2.56
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
LT1963A-3.3 Output Voltage
3.38 IL = 1mA 3.36
ADJ PIN VOLTAGE (V)
LT1963A ADJ Pin Voltage
1.230 IL = 1mA 1.225 1.220 1.215 1.210 1.205 1.200 1.195
2.54 2.52 2.50 2.48 2.46 2.44 2.42 -50 -25 0 25 50 75 100 125
3.34 3.32 3.30 3.28 3.26 3.24 3.22 -50 -25 0 25 50 75 100 125
1.190 -50
-25
0
25
50
75
100
125
TEMPERATURE (C)
1963A G06
TEMPERATURE (C)
1963A G07
TEMPERATURE (C)
1963A G08
1963afd
7
LT1963A Series TYPICAL PERFORMANCE CHARACTERISTICS
LT1963A-1.5 Quiescent Current
14 TJ = 25C R = 12 L VSHDN = VIN 10 8 6 4 2 0 0 1 2 3456 7 INPUT VOLTAGE (V) 8 9
14 12
LT1963A-1.8 Quiescent Current
TJ = 25C RL = VSHDN = VIN 14 12
LT1963A-2.5 Quiescent Current
TJ = 25C RL = VSHDN = VIN
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
10 8 6 4 2 0 0 1 2
10 8 6 4 2 0
10
34567 INPUT VOLTAGE (V)
8
9
10
0
1
2
34567 INPUT VOLTAGE (V)
8
9
10
1963A G41
1963A G09
1963A G10
LT1963A-3.3 Quiescent Current
14 12 TJ = 25C RL = VSHDN = VIN
LT1963A Quiescent Current
1.4 1.2
25
LT1963A-1.5 GND Pin Current
TJ = 25C VSHDN = VIN *FOR VOUT = 1.5V
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
TJ = 25C RL = 4.3k VSHDN = VIN
GND PIN CURRENT (mA)
20
10 8 6 4 2 0 0 1 2
1.0 0.8 0.6 0.4 0.2
15 RL = 150, IL = 10mA* 10 RL = 5, IL = 300mA* RL = 15, IL = 100mA*
5
34567 INPUT VOLTAGE (V)
8
9
10
0 0 2 4
0
6 8 10 12 14 16 18 20 INPUT VOLTAGE (V)
1963A G12
0
1
2
34567 INPUT VOLTAGE (V)
8
9
10
1963A G11
1963A G42
LT1963A-1.8 GND Pin Current
25 TJ = 25C VSHDN = VIN 20 *FOR VOUT = 1.8V
GND PIN CURRENT (mA)
LT1963A-2.5 GND Pin Current
25 25 TJ = 25C VSHDN = VIN *FOR VOUT = 2.5V
GND PIN CURRENT (mA)
LT1963A-3.3 GND Pin Current
TJ = 25C VSHDN = VIN *FOR VOUT = 3.3V
GND PIN CURRENT (mA)
20
20
15
15
15 RL = 11, IL = 300mA*
RL = 8.33, IL = 300mA*
10
RL = 6, IL = 300mA* RL = 18, IL = 100mA* RL = 180, IL = 10mA*
10 RL = 25, IL = 100mA*
10
5
5
5
RL = 33, IL = 100mA* RL = 330, IL = 100mA* 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10
1963A G15
0 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10
1963A G13
0 0 1 2
RL = 250, IL = 10mA* 34567 INPUT VOLTAGE (V) 8 9 10
1963A G14
0
1963afd
8
LT1963A Series TYPICAL PERFORMANCE CHARACTERISTICS
LT1963A GND Pin Current
10 TJ = 25C VSHDN = VIN *FOR VOUT = 1.21V
100 90
LT1963A-1.5 GND Pin Current
100 TJ = 25C VSHDN = VIN *FOR VOUT = 1.5V 90
LT1963A-1.8 GND Pin Current
TJ = 25C VSHDN = VIN *FOR VOUT = 1.8V
GND PIN CURRENT (mA)
GND PIN CURRENT (mA)
GND PIN CURRENT (mA)
8
80 70 60 50 40 30 20
80 70 60 50 40 30 20 10 0
6
RL = 4.33, IL = 300mA*
RL = 1, IL = 1.5A* RL = 1.5, IL = 1A*
RL = 1.2, IL = 1.5A*
4 RL = 12.1, IL = 100mA* 2 RL = 121, IL = 10mA* 0 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10
1963A G16
RL = 1.8, IL = 1A*
RL = 3, IL = 500mA*
10 0 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10
RL = 3.6, IL = 500mA* 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10
1963A G43
1963A G17
LT1963A-2.5 GND Pin Current
100 90 TJ = 25C VSHDN = VIN *FOR VOUT = 2.5V RL = 1.67, IL = 1.5A*
100 90
LT1963A-3.3 GND Pin Current
TJ = 25C VSHDN = VIN *FOR VOUT = 3.3V
LT1963A GND Pin Current
100 90 TJ = 25C VSHDN = VIN *FOR VOUT = 1.21V
GND PIN CURRENT (mA)
GND PIN CURRENT (mA)
70 60 50 40 30 20 10 0 0 1 2
70 60 50 40 30 20
GND PIN CURRENT (mA)
80
80
80 70 60 50 40 30 20
RL = 2.2, IL = 1.5A*
RL = 0.81, IL = 1.5A*
RL = 2.5, IL = 1A*
RL = 3.3, IL = 1A*
RL = 1.21, IL = 1A* RL = 2.42, IL = 500mA* 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10
RL = 5, IL = 500mA* 34567 INPUT VOLTAGE (V) 8 9 10
10 0 0 1 2
RL = 6.6, IL = 500mA* 34567 INPUT VOLTAGE (V) 8 9 10
10 0
1963A G18
1963A G19
1963A G20
GND Pin Current vs ILOAD
100 90
SHDN Pin Threshold (On-to-Off)
1.0 0.9 IL = 1mA 1.0 0.9
SHDN Pin Threshold (Off-to-On)
IL = 1.5A
VIN = VOUT (NOMINAL) +1V
SHDN PIN THRESHOLD (V)
70 60 50 40 30 20 10 0 0 0.2 0.4 0.6 0.8 1.0 1.2 OUTPUT CURRENT (A) 1.4 1.6
0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -50 -25 50 25 0 75 TEMPERATURE (C) 100 125
SHDN PIN THRESHOLD (V)
GND PIN CURRENT (mA)
80
0.8
0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -50 -25 50 25 0 75 TEMPERATURE (C) 100 125 IL = 1mA
1963A G21
1963A G22
1963A G23
1963afd
9
LT1963A Series TYPICAL PERFORMANCE CHARACTERISTICS
SHDN Pin Input Current
5.0 4.5 7
SHDN PIN INPUT CURRENT (A)
SHDN Pin Input Current
VSHDN = 20V
ADJ PIN BIAS CURRENT (A)
ADJ Pin Bias Current
5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5
SHDN PIN INPUT CURRENT (A)
6 5 4 3 2 1 0 -50 -25
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 0 2 4 6 8 10 12 14 16 18 20 SHDN PIN VOLTAGE (V)
1963A G24
50 25 75 0 TEMPERATURE (C)
100
125
0 -50
-25
50 25 0 75 TEMPERATURE (C)
100
125
1963A G25
1963A G26
Current Limit
3.0 2.5
Current Limit
4.0 VIN = 7V 3.5 VOUT = 0V
CURRENT LIMIT (A)
2.0 TJ = 125C 1.5 1.0 0.5 VOUT = 100mV 0 0 2
TJ = -50C
CURRENT LIMIT (A)
TJ = 25C
3.0 2.5 2.0 1.5 1.0 0.5 0 -50 -25 50 25 0 75 TEMPERATURE (C) 100 125
4 6 8 10 12 14 16 18 20 INPUT/OUTPUT DIFFERENTIAL (V)
1963A G27
1963A G28
Reverse Output Current
5.0
REVERSE OUTPUT CURRENT (mA)
Reverse Output Current
1.0 VIN = 0V 0.9 VOUT = 1.21V (LT1963A) V = 1.5V (LT1963A-1.5) 0.8 VOUT = 1.8V (LT1963A-1.8) OUT 0.7 VOUT = 2.5V (LT1963A-2.5) VOUT = 3.3V (LT1963A-3.3) 0.6 LT1963A-1.8/-2.5/-3.3 0.5 0.4 0.3 0.2 0.1 0 -50 -25 50 25 0 75 TEMPERATURE (C) 100 125 LT1963A
LT1963A-1.8 LT1963A-1.5
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 0
LT1963A
LT1963A-3.3 T = 25C J VIN = 0V LT1963A-2.5 CURRENT FLOWS INTO OUTPUT PIN VOUT = VADJ (LT1963A) VOUT = VFB (LT1963A-1.5/1.8/-2.5/-3.3) 1 2 345678 OUTPUT VOLTAGE (V) 9 10
1963A G29
REVERSE OUTPUT CURRENT (mA)
4.5
1963A G30
1963afd
10
LT1963A Series TYPICAL PERFORMANCE CHARACTERISTICS
Ripple Rejection
80 70
76 74
RIPPLE REJECTION (dB)
Ripple Rejection
3.0 2.5 2.0 1.5 1.0 0.5
LT1963A Minimum Input Voltage
MINIMUM INPUT VOLTAGE (V)
RIPPLE REJECTION (dB)
60 50 40 30 20 COUT = 100F TANTALUM +10 x 1F CERAMIC COUT = 10F TANTALUM
IL = 1.5A
72 70 68 66 64 IL = 0.75A VIN = VOUT(NOMINAL) +1V + 0.5VP-P RIPPLE AT f = 120Hz 62 50 100 25 75 -50 -25 0 TEMPERATURE (C)
IL = 500mA
IL = 100mA
10 IL = 0.75A VIN = VOUT(NOMINAL) +1V + 50mVRMS RIPPLE 0 100 100k 10 1k 10k 1M FREQUENCY (Hz)
1963A G31
125
0 -50 -25
50 25 75 0 TEMPERATURE (C)
100
125
1963A G32
1963A G33
Load Regulation
OUTPUT NOISE SPECTRAL DENSITY (V/Hz)
10 5
LOAD REGULATION (mV)
Output Noise Spectral Density
1.0 COUT = 10F IL =1.5A
LT1963A-1.5 LT1963A LT1963A-1.8
0 -5 -10 -15
LT1963A-3.3 0.1
LT1963A-2.5
LT1963A-2.5 LT1963A-3.3 VIN = VOUT(NOMINAL) +1V (LT1963A-1.8/-2.5/-3.3) VIN = 2.7V (LT1963A/LT1963A-1.5) IL = 1mA TO 1.5A 50 25 75 0 TEMPERATURE (C) 100 125
LT1963A-1.8 LT1963A-1.5 0.01 10 100
LT1963A
-20 -50 -25
1k 10k FREQUENCY (Hz)
100k
1963A G35
1963A G34
RMS Output Noise vs Load Current (10Hz to 100kHz)
50
LT1963A-3.3 10Hz to 100kHz Output Noise
OUTPUT NOISE VOLTAGE (VRMS)
45 40 35 30 25 20 15 10 5
COUT = 10F LT1963A-3.3 LT1963A-2.5 LT1963A-1.8 LT1963A-1.5 LT1963A
VOUT 100V/DIV
0 0.0001
0.001
0.01 0.1 LOAD CURRENT (A)
1
10
1963A G36
COUT = 10F ILOAD = 1.5A
1ms/DIV
1963A G37
1963afd
11
LT1963A Series TYPICAL PERFORMANCE CHARACTERISTICS
LT1963A-3.3 Transient Response
200
OUTPUT VOLTAGE DEVIATION (mV) OUTPUT VOLTAGE DEVIATION (mV)
LT1963A-3.3 Transient Response
150 100 50 0 -50
VIN = 4.3V 150 CIN = 3.3F TANTALUM COUT = 10F TANTALUM 100 50 0 -50
-100 -150
-100
LOAD CURRENT (A)
LOAD CURRENT (A)
0.6 0.4 0.2 0 0 2 4 6 8 10 12 14 16 18 20 TIME (s)
1963A G38
1.5 1.0 0.5 0 0
VIN = 4.3V CIN = 33F TANTALUM COUT = 100F TANTALUM +10 x 1F CERAMIC 50 100 150 200 250 300 350 400 450 500 TIME (s)
1963A G39
1963afd
12
LT1963A Series PIN FUNCTIONS
OUT: Output. The output supplies power to the load. A minimum output capacitor of 10F is required to prevent oscillations. Larger output capacitors will be required for applications with large transient loads to limit peak voltage transients. See the Applications Information section for more information on output capacitance and reverse output characteristics. SENSE: Sense. For fixed voltage versions of the LT1963A (LT1963A-1.5/LT1963A-1.8/LT1963A-2.5/LT1963A-3.3), the SENSE pin is the input to the error amplifier. Optimum regulation will be obtained at the point where the SENSE pin is connected to the OUT pin of the regulator. In critical applications, small voltage drops are caused by the resistance (RP) of PC traces between the regulator and the load. These may be eliminated by connecting the SENSE pin to the output at the load as shown in Figure 1 (Kelvin Sense Connection). Note that the voltage drop across the external PC traces will add to the dropout voltage of the regulator. The SENSE pin bias current is 600A at the nominal rated output voltage. The SENSE pin can be pulled below ground (as in a dual supply system where the regulator load is returned to a negative supply) and still allow the device to start and operate. ADJ: Adjust. For the adjustable LT1963A, this is the input to the error amplifier. This pin is internally clamped to 7V. It has a bias current of 3A which flows into the pin. The ADJ pin voltage is 1.21V referenced to ground and the output voltage range is 1.21V to 20V. SHDN: Shutdown. The SHDN pin is used to put the LT1963A regulators into a low power shutdown state. The output will be off when the SHDN pin is pulled low. The SHDN pin can be driven either by 5V logic or open-collector logic with a pull-up resistor. The pull-up resistor is required to supply the pull-up current of the open-collector gate, normally several microamperes, and the SHDN pin current, typically 3A. If unused, the SHDN pin must be connected to VIN. The device will be in the low power shutdown state if the SHDN pin is not connected. IN: Input. Power is supplied to the device through the IN pin. A bypass capacitor is required on this pin if the device is more than six inches away from the main input filter capacitor. In general, the output impedance of a battery rises with frequency, so it is advisable to include a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1F to 10F is sufficient. The LT1963A regulators are designed to withstand reverse voltages on the IN pin with respect to ground and the OUT pin. In the case of a reverse input, which can happen if a battery is plugged in backwards, the device will act as if there is a diode in series with its input. There will be no reverse current flow into the regulator and no reverse voltage will appear at the load. The device will protect both itself and the load.
IN OUT LT1963A RP
+
VIN
SHDN
SENSE GND RP
+
LOAD
1963A F01
Figure 1. Kelvin Sense Connection
1963afd
13
LT1963A Series APPLICATIONS INFORMATION
The LT1963A series are 1.5A low dropout regulators optimized for fast transient response. The devices are capable of supplying 1.5A at a dropout voltage of 350mV. The low operating quiescent current (1mA) drops to less than 1A in shutdown. In addition to the low quiescent current, the LT1963A regulators incorporate several protection features which make them ideal for use in battery-powered systems. The devices are protected against both reverse input and reverse output voltages. In battery backup applications where the output can be held up by a backup battery when the input is pulled to ground, the LT1963A-X acts like it has a diode in series with its output and prevents reverse current flow. Additionally, in dual supply applications where the regulator load is returned to a negative supply, the output can be pulled below ground by as much as 20V and still allow the device to start and operate. Adjustable Operation The adjustable version of the LT1963A has an output voltage range of 1.21V to 20V. The output voltage is set by the ratio of two external resistors as shown in Figure 2. The device servos the output to maintain the voltage at the ADJ pin at 1.21V referenced to ground. The current in R1 is then equal to 1.21V/R1 and the current in R2 is the current in R1 plus the ADJ pin bias current. The ADJ pin bias current, 3A at 25C, flows through R2 into the ADJ pin. The output voltage can be calculated using the formula in Figure 2. The value of R1 should be less than 4.17k to minimize errors in the output voltage caused by the ADJ pin bias current. Note that in shutdown the output is turned off and the divider current will be zero. The adjustable device is tested and specified with the ADJ pin tied to the OUT pin for an output voltage of 1.21V. Specifications for output voltages greater than 1.21V will be proportional to the ratio of the desired output voltage to 1.21V: VOUT/1.21V. For example, load regulation for an output current change of 1mA to 1.5A is - 3mV typical at VOUT = 1.21V. At VOUT = 5V, load regulation is: (5V/1.21V)(-3mV) = -12.4mV Output Capacitors and Stability The LT1963A regulator is a feedback circuit. Like any feedback circuit, frequency compensation is needed to
IN VIN OUT LT1963A ADJ GND R1 R2 VOUT
+
VOUT =1.21V 1+ VADJ =1.21V IADJ = 3A AT 25C OUTPUT RANGE = 1.21V TO 20V R2 + (IADJ ) (R2) R1
1963A F02
Figure 2. Adjustable Operation
make it stable. For the LT1963A, the frequency compensation is both internal and external--the output capacitor. The size of the output capacitor, the type of the output capacitor, and the ESR of the particular output capacitor all affect the stability. In addition to stability, the output capacitor also affects the high frequency transient response. The regulator loop has a finite band width. For high frequency transient loads, recovery from a transient is a combination of the output capacitor and the bandwidth of the regulator. The LT1963A was designed to be easy to use and accept a wide variety of output capacitors. However, the frequency compensation is affected by the output capacitor and optimum frequency stability may require some ESR, especially with ceramic capacitors. For ease of use, low ESR polytantalum capacitors (POSCAP) are a good choice for both the transient response and stability of the regulator. These capacitors have intrinsic ESR that improves the stability. Ceramic capacitors have extremely low ESR, and while they are a good choice in many cases, placing a small series resistance element will sometimes achieve optimum stability and minimize ringing. In all cases, a minimum of 10F is required while the maximum ESR allowable is 3. The place where ESR is most helpful with ceramics is low output voltage. At low output voltages, below 2.5V, some ESR helps the stability when ceramic output capacitors are used. Also, some ESR allows a smaller capacitor value to be used. When small signal ringing occurs with ceramics due to insufficient ESR, adding ESR or increasing the capacitor value improves the stability and reduces the ringing. Table 1 gives some recommended values of ESR to minimize ringing caused by fast, hard current transitions.
1963afd
14
LT1963A Series APPLICATIONS INFORMATION
Table 1. Capacitor Minimum ESR
VOUT 1.2V 1.5V 1.8V 2.5V 3.3V 5V 10F 20m 20m 15m 5m 0m 0m 22F 15m 15m 10m 5m 0m 0m 47F 10m 10m 10m 5m 0m 0m 100F 5m 5m 5m 5m 5m 0m
POSCAP capacitors are used. The output voltage is at the worst case value of 1.2V. Trace A, is with a 10F ceramic output capacitor and shows significant ringing with a peak amplitude of 25mV. For Trace B, a 22F/45m POSCAP is added in parallel with the 10F ceramic. The output is well damped and settles to within 10mV in less than 20s. For Trace C, a 100F/35m POSCAP is connected in parallel with the 10F ceramic capacitor. In this case the peak output deviation is less than 20mV and the output settles in about 10s. For improved transient response the value of the bulk capacitor (tantalum or aluminum electrolytic) should be greater than twice the value of the ceramic capacitor. Tantalum and Polytantalum Capacitors There is a variety of tantalum capacitor types available, with a wide range of ESR specifications. Older types have ESR specifications in the hundreds of m to several Ohms. Some newer types of polytantalum with multi-electrodes have maximum ESR specifications as low as 5m. In general the lower the ESR specification, the larger the size and the higher the price. Polytantalum capacitors have better surge capability than older types and generally lower ESR. Some types such as the Sanyo TPE and TPB series have ESR specifications in the 20m to 50m range, which provide near optimum transient response. Aluminum Electrolytic Capacitors Aluminum electrolytic capacitors can also be used with the LT1963A. These capacitors can also be used in conjunction with ceramic capacitors. These tend to be the cheapest and lowest performance type of capacitors. Care must be used in selecting these capacitors as some types can have ESR which can easily exceed the 3 maximum value. Ceramic Capacitors Extra consideration must be given to the use of ceramic capacitors. Ceramic capacitors are manufactured with a variety of dielectrics, each with different behavior over temperature and applied voltage. The most common dielectrics used are Z5U, Y5V, X5R and X7R. The Z5U and
1963afd
Figures 3 through 8 show the effect of ESR on the transient response of the regulator. These scope photos show the transient response for the LT1963A at three different output voltages with various capacitors and various values of ESR. The output load conditions are the same for all traces. In all cases there is a DC load of 500mA. The load steps up to 1A at the first transition and steps back to 500mA at the second transition. At the worst case point of 1.2VOUT with 10F COUT (Figure 3), a minimum amount of ESR is required. While 20m is enough to eliminate most of the ringing, a value closer to 50m provides a more optimum response. At 2.5V output with 10F COUT (Figure 4) the output rings at the transitions with 0 ESR but still settles to within 10mV in 20s after the 0.5A load step. Once again a small value of ESR will provide a more optimum response. At 5VOUT with 10F COUT (Figure 5) the response is well damped with 0 ESR. With a COUT of 100F at 0 ESR and an output of 1.2V (Figure 6), the output rings although the amplitude is only 20mVp-p. With COUT of 100F it takes only 5m to 20m of ESR to provide good damping at 1.2V output. Performance at 2.5V and 5V output with 100F COUT shows similar characteristics to the 10F case (see Figures 7-8). At 2.5VOUT 5m to 20m can improve transient response. At 5VOUT the response is well damped with 0 ESR. Capacitor types with inherently higher ESR can be combined with 0m ESR ceramic capacitors to achieve both good high frequency bypassing and fast settling time. Figure 9 illustrates the improvement in transient response that can be seen when a parallel combination of ceramic and
15
LT1963A Series APPLICATIONS INFORMATION
0 20 RESR (m) 50mV/DIV VOUT = 1.2V IOUT = 500mA WITH 500mA PULSE COUT = 10F RESR (m) 0 5 50mV/DIV VOUT = 1.2V IOUT = 500mA WITH 500mA PULSE COUT = 100F
50
10
100
20
20s/DIV
1963A F03
1963A F06
50s/DIV
Figure 3
Figure 6
0
20 RESR (m) 50mV/DIV
VOUT = 2.5V IOUT = 500mA WITH 500mA PULSE COUT = 10F RESR (m)
0
5 50mV/DIV
VOUT = 2.5V IOUT = 500mA WITH 500mA PULSE COUT = 100F
50
10
100
20
20s/DIV
1963A F04
50s/DIV
1963A F07
Figure 4
Figure 7
0
20 50mV/DIV RESR (m)
VOUT = 5V IOUT = 500mA WITH 500mA PULSE COUT = 10F RESR (m)
0
5 50mV/DIV
VOUT = 5V IOUT = 500mA WITH 500mA PULSE COUT = 100F
50
10
100
20
20s/DIV
1963A F05
1963A F08
50s/DIV
Figure 5
A
Figure 8
B 50mV/DIV RESR (m)
VOUT = 1.2V IOUT = 500mA WITH 500mA PULSE COUT = A = 10F CERAMIC B = 10F CERAMIC II 22F/45m POLY C = 10F CERAMIC II 100F/35m POLY
C
50s/DIV
1963A F09
Figure 9
1963afd
16
LT1963A Series APPLICATIONS INFORMATION
Y5V dielectrics are good for providing high capacitances in a small package, but exhibit strong voltage and temperature coefficients as shown in Figures 10 and 11. When used with a 5V regulator, a 10F Y5V capacitor can exhibit an effective value as low as 1F to 2F over the operating temperature range. The X5R and X7R dielectrics result in more stable characteristics and are more suitable for use as the output capacitor. The X7R type has better stability across temperature, while the X5R is less expensive and is available in higher values. Voltage and temperature coefficients are not the only sources of problems. Some ceramic capacitors have a piezoelectric response. A piezoelectric device generates voltage across its terminals due to mechanical stress, similar to the way a piezoelectric accelerometer or microphone works. For a ceramic capacitor the stress can be induced by vibrations in the system or thermal transients.
Table 2. PC Trace Resistors
10m 0.5oz CU 1.0oz CU 2.0oz CU Width Length Width Length Width Length 0.011" (0.28mm) 0.102" (2.6mm) 0.006" (0.15mm) 0.110" (2.8mm) 0.006" (0.15mm) 0.224" (5.7mm) 20m 0.011" (0.28mm) 0.204" (5.2mm) 0.006" (0.15mm) 0.220" (5.6mm) 0.006" (0.15mm) 0.450" (11.4mm) 30m 0.011" (0.28mm) 0.307" (7.8mm) 0.006" (0.15mm) 0.330" (8.4mm) 0.006" (0.15mm) 0.670" (17mm)
"FREE" Resistance with PC Traces The resistance values shown in Table 2 can easily be made using a small section of PC trace in series with the output capacitor. The wide range of non-critical ESR makes it easy to use PC trace. The trace width should be sized to handle the RMS ripple current associated with the load. The output capacitor only sources or sinks current for a few microseconds during fast output current transitions. There is no DC current in the output capacitor. Worst case ripple current will occur if the output load is a high frequency (>100kHz) square wave with a high peak value and fast edges (< 1s). Measured RMS value for this case is 0.5 times the peak-to-peak current change. Slower edges or lower frequency will significantly reduce the RMS ripple current in the capacitor.
20 0
CHANGE IN VALUE (%)
BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10F
CHANGE IN VALUE (%)
40 20 0 -20 -40 -60 -80 BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10F 50 25 75 0 TEMPERATURE (C) 100 125 Y5V X5R
X5R -20 -40 -60 Y5V -80
-100
0
2
4
8 6 10 12 DC BIAS VOLTAGE (V)
14
16
-100 -50 -25
1963A F10
1963A F11
Figure 10. Ceramic Capacitor DC Bias Characteristics
Figure 11. Ceramic Capacitor Temperature Characteristics
1963afd
17
LT1963A Series APPLICATIONS INFORMATION
This resistor should be made using one of the inner layers of the PC board which are well defined. The resistivity is determined primarily by the sheet resistance of the copper laminate with no additional plating steps. Table 2 gives some sizes for 0.75A RMS current for various copper thicknesses. More detailed information regarding resistors made from PC traces can be found in Application Note 69, Appendix A. Overload Recovery Like many IC power regulators, the LT1963A-X has safe operating area protection. The safe area protection decreases the current limit as input-to-output voltage increases and keeps the power transistor inside a safe operating region for all values of input-to-output voltage. The protection is designed to provide some output current at all values of input-to-output voltage up to the device breakdown. When power is first turned on, as the input voltage rises, the output follows the input, allowing the regulator to start up into very heavy loads. During the start-up, as the input voltage is rising, the input-to-output voltage differential is small, allowing the regulator to supply large output currents. With a high input voltage, a problem can occur wherein removal of an output short will not allow the output voltage to recover. Other regulators, such as the LT1085, also exhibit this phenomenon, so it is not unique to the LT1963A-X. The problem occurs with a heavy output load when the input voltage is high and the output voltage is low. Common situations are immediately after the removal of a shortcircuit or when the shutdown pin is pulled high after the input voltage has already been turned on. The load line for such a load may intersect the output current curve at two points. If this happens, there are two stable output operating points for the regulator. With this double intersection, the input power supply may need to be cycled down to zero and brought up again to make the output recover. Output Voltage Noise The LT1963A regulators have been designed to provide low output voltage noise over the 10Hz to 100kHz bandwidth while operating at full load. Output voltage noise is typically 40nV/Hz over this frequency bandwidth for the LT1963A (adjustable version). For higher output voltages (generated by using a resistor divider), the output voltage noise will be gained up accordingly. This results in RMS noise over the 10Hz to 100kHz bandwidth of 14VRMS for the LT1963A increasing to 38VRMS for the LT1963A-3.3. Higher values of output voltage noise may be measured when care is not exercised with regard to circuit layout and testing. Crosstalk from nearby traces can induce unwanted noise onto the output of the LT1963A-X. Power supply ripple rejection must also be considered; the LT1963A regulators do not have unlimited power supply rejection and will pass a small portion of the input noise through to the output. Thermal Considerations The power handling capability of the device is limited by the maximum rated junction temperature (125C). The power dissipated by the device is made up of two components: 1. Output current multiplied by the input/output voltage differential: (IOUT)(VIN - VOUT), and 2. GND pin current multiplied by the input voltage: (IGND)(VIN). The GND pin current can be found using the GND Pin Current curves in the Typical Performance Characteristics. Power dissipation will be equal to the sum of the two components listed above. The LT1963A series regulators have internal thermal limiting designed to protect the device during overload conditions. For continuous normal conditions, the maximum junction temperature rating of 125C must not be exceeded. It is important to give careful consideration to all sources of thermal resistance from junction to ambient. Additional heat sources mounted nearby must also be considered. For surface mount devices, heat sinking is accomplished by using the heat spreading capabilities of the PC board and its copper traces. Copper board stiffeners and plated through-holes can also be used to spread the heat generated by power devices.
1963afd
18
LT1963A Series APPLICATIONS INFORMATION
The following tables list thermal resistance for several different board sizes and copper areas. All measurements were taken in still air on 1/16" FR-4 board with one ounce copper.
Table 3. Q Package, 5-Lead DD
COPPER AREA TOPSIDE* BACKSIDE 2500mm2 1000mm2 125mm2 2500mm2 2500mm2 2500mm2 BOARD AREA 2500mm2 2500mm2 2500mm2 THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 23C/W 25C/W 33C/W
The power dissipated by the device will be equal to: IOUT(MAX)(VIN(MAX) - VOUT) + IGND(VIN(MAX)) where, IOUT(MAX) = 500mA VIN(MAX) = 6V IGND at (IOUT = 500mA, VIN = 6V) = 10mA So, P = 500mA(6V - 3.3V) + 10mA(6V) = 1.41W Using a DD package, the thermal resistance will be in the range of 23C/W to 33C/W depending on the copper area. So the junction temperature rise above ambient will be approximately equal to: 1.41W(28C/W) = 39.5C The maximum junction temperature will then be equal to the maximum junction temperature rise above ambient plus the maximum ambient temperature or: TJMAX = 50C + 39.5C = 89.5C Protection Features
*Device is mounted on topside
Table 4. S0-8 Package, 8-Lead SO
COPPER AREA TOPSIDE* BACKSIDE 2500mm2 1000mm2 225mm2 125mm2 2500mm2 2500mm2 2500mm2 2500mm2 BOARD AREA 2500mm2 2500mm2 2500mm2 2500mm2 THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 55C/W 55C/W 63C/W 69C/W
*Device is mounted on topside
Table 5. SOT-223 Package, 3-Lead SOT-223
COPPER AREA TOPSIDE* BACKSIDE 2500mm2 1000mm2 225mm2 100mm2 1000mm2 1000mm2 2500mm2 2500mm2 2500mm2 2500mm2 1000mm2 0mm2 BOARD AREA 2500mm2 2500mm2 2500mm2 2500mm2 1000mm2 1000mm2 THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 42C/W 42C/W 50C/W 56C/W 49C/W 52C/W
The LT1963A regulators incorporate several protection features which make them ideal for use in battery-powered circuits. In addition to the normal protection features associated with monolithic regulators, such as current limiting and thermal limiting, the devices are protected against reverse input voltages, reverse output voltages and reverse voltages from output to input. Current limit protection and thermal overload protection are intended to protect the device against current overload conditions at the output of the device. For normal operation, the junction temperature should not exceed 125C. The input of the device will withstand reverse voltages of 20V. Current flow into the device will be limited to less than 1mA (typically less than 100A) and no negative voltage will appear at the output. The device will protect both itself and the load. This provides protection against batteries that can be plugged in backward.
*Device is mounted on topside
T Package, 5-Lead TO-220
Thermal Resistance (Junction-to-Case) = 4C/W
Calculating Junction Temperature Example: Given an output voltage of 3.3V, an input voltage range of 4V to 6V, an output current range of 0mA to 500mA and a maximum ambient temperature of 50C, what will the maximum junction temperature be?
1963afd
19
LT1963A Series APPLICATIONS INFORMATION
The output of the LT1963A can be pulled below ground without damaging the device. If the input is left open circuit or grounded, the output can be pulled below ground by 20V. For fixed voltage versions, the output will act like a large resistor, typically 5k or higher, limiting current flow to typically less than 600A. For adjustable versions, the output will act like an open circuit; no current will flow out of the pin. If the input is powered by a voltage source, the output will source the short-circuit current of the device and will protect itself by thermal limiting. In this case, grounding the SHDN pin will turn off the device and stop the output from sourcing the short-circuit current. The ADJ pin of the adjustable device can be pulled above or below ground by as much as 7V without damaging the device. If the input is left open circuit or grounded, the ADJ pin will act like an open circuit when pulled below ground and like a large resistor (typically 5k) in series with a diode when pulled above ground. In situations where the ADJ pin is connected to a resistor divider that would pull the ADJ pin above its 7V clamp voltage if the output is pulled high, the ADJ pin input current must be limited to less than 5mA. For example, a resistor divider is used to provide a regulated 1.5V output from the 1.21V reference when the output is forced to 20V. The top resistor of the resistor divider must be chosen to limit the current into the ADJ pin to less than 5mA when the ADJ pin is at 7V. The 13V difference between OUT and ADJ pins divided by the 5mA maximum current into the ADJ pin yields a minimum top resistor value of 2.6k. In circuits where a backup battery is required, several different input/output conditions can occur. The output voltage may be held up while the input is either pulled to ground, pulled to some intermediate voltage, or is left open circuit. Current flow back into the output will follow the curve shown in Figure 12. When the IN pin of the LT1963A is forced below the OUT pin or the OUT pin is pulled above the IN pin, input current will typically drop to less than 2A. This can happen if the input of the device is connected to a discharged (low voltage) battery and the output is held up by either a backup battery or a second regulator circuit. The state of the SHDN pin will have no effect on the reverse output current when the output is pulled above the input.
5.0 LT1963A VOUT = VADJ
REVERSE OUTPUT CURRENT (mA)
4.5
4.0 LT1963A-1.5 VOUT = VFB 3.5 LT1963A-1.8 3.0 VOUT = VFB 2.5 LT1963A-2.5 VOUT = VFB 2.0 1.5 1.0 0.5 0 0 1 2
LT1963A-3.3 VOUT = VFB TJ = 25C VIN = 0V CURRENT FLOWS INTO OUTPUT PIN 9 10
345678 OUTPUT VOLTAGE (V)
1963A F12
Figure 12. Reverse Output Current
1963afd
20
LT1963A Series TYPICAL APPLICATIONS
SCR Pre-Regulator Provides Efficiency Over Line Variations
L1 500H L2 10VAC AT 115VIN 90-140 VAC 10VAC AT 115VIN 1N4148 1k 34k* LT1963A-3.3 IN OUT
+
10000F
SHDN GND
FB
+
3.3VOUT 1.5A 22F
1N4002 "SYNC" 1N4002 TO ALL "+V" POINTS + 22F
1N4002 +V 2.4k
12.1k*
+
750
C1A 1/2 LT1018 1N4148
200k
-
+V C1B 0.033F 750
0.1F
+V 1N4148
LT1006 10k 1F +V
L1 = COILTRONICS CTX500-2-52 L2 = STANCOR P-8559 * = 1% FILM RESISTOR = NTE5437
-
+
10k 10k +V LT1004 1.2V
1963A TA03
1/2 LT1018
-
+
A1
1963afd
21
LT1963A Series TYPICAL APPLICATIONS
Paralleling of Regulators for Higher Output Current
R1 0.01
+
VIN > 3.7V
LT1963A-3.3 IN OUT
C1 100F
+
SHDN GND
FB
3.3V 3A C2 22F
R2 0.01 IN SHDN
LT1963A OUT R6 6.65k
SHDN GND
FB R7 4.12k
R3 2.2k
R4 2.2k 3
R5 1k
+ -
8 1/2 LT1366 4 1 C3 0.01F
1963A TA05
2
1963afd
22
LT1963A Series PACKAGE DESCRIPTION
Q Package 5-Lead Plastic DD Pak
(Reference LTC DWG # 05-08-1461)
.256 (6.502)
.060 (1.524)
.060 (1.524) TYP
.390 - .415 (9.906 - 10.541) 15 TYP
.165 - .180 (4.191 - 4.572)
.045 - .055 (1.143 - 1.397)
.060 (1.524)
.183 (4.648)
.330 - .370 (8.382 - 9.398)
.059 (1.499) TYP
(
+.008 .004 -.004 +0.203 0.102 -0.102
)
.075 (1.905) .300 (7.620) BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK +.012 .143 -.020 +0.305 3.632 -0.508 .067 (1.702) .028 - .038 BSC (0.711 - 0.965) TYP
.013 - .023 (0.330 - 0.584)
.095 - .115 (2.413 - 2.921)
.050 .012 (1.270 0.305)
Q(DD5) 0502
(
)
.420
.080
.420 .276
.350 .205 .565
.325 .565
.320 .090 .067 .042 .067 .090 .042
RECOMMENDED SOLDER PAD LAYOUT NOTE: 1. DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE
RECOMMENDED SOLDER PAD LAYOUT FOR THICKER SOLDER PASTE APPLICATIONS
1963afd
23
LT1963A Series PACKAGE DESCRIPTION
S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.045 .005 .050 BSC 8
.189 - .197 (4.801 - 5.004) NOTE 3 7 6 5
.245 MIN
.160 .005 .228 - .244 (5.791 - 6.197)
.150 - .157 (3.810 - 3.988) NOTE 3
.030 .005 TYP RECOMMENDED SOLDER PAD LAYOUT .010 - .020 x 45 (0.254 - 0.508) .008 - .010 (0.203 - 0.254)
0- 8 TYP
1
2
3
4
.053 - .069 (1.346 - 1.752)
.004 - .010 (0.101 - 0.254)
.016 - .050 (0.406 - 1.270)
NOTE: 1. DIMENSIONS IN
INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
.014 - .019 (0.355 - 0.483) TYP
.050 (1.270) BSC
SO8 0303
1963afd
24
LT1963A Series PACKAGE DESCRIPTION
ST Package 3-Lead Plastic SOT-223
(Reference LTC DWG # 05-08-1630)
.248 - .264 (6.30 - 6.71) .114 - .124 (2.90 - 3.15) .059 MAX
.129 MAX
.264 - .287 (6.70 - 7.30) .130 - .146 (3.30 - 3.71)
.248 BSC
.039 MAX
.059 MAX .090 BSC
.181 MAX .0905 (2.30) BSC .071 (1.80) MAX .033 - .041 (0.84 - 1.04)
RECOMMENDED SOLDER PAD LAYOUT 10 - 16
10 MAX
.010 - .014 (0.25 - 0.36)
10 - 16 .024 - .033 (0.60 - 0.84) .181 (4.60) BSC .012 (0.31) MIN .0008 - .0040 (0.0203 - 0.1016)
ST3 (SOT-233) 0502
1963afd
25
LT1963A Series PACKAGE DESCRIPTION
T Package 5-Lead Plastic TO-220 (Standard)
(Reference LTC DWG # 05-08-1421)
.390 - .415 (9.906 - 10.541)
.147 - .155 (3.734 - 3.937) DIA .230 - .270 (5.842 - 6.858)
.165 - .180 (4.191 - 4.572)
.045 - .055 (1.143 - 1.397)
.460 - .500 (11.684 - 12.700)
.570 - .620 (14.478 - 15.748) .330 - .370 (8.382 - 9.398) .700 - .728 (17.78 - 18.491)
.620 (15.75) TYP
SEATING PLANE .152 - .202 .260 - .320 (3.861 - 5.131) (6.60 - 8.13)
.095 - .115 (2.413 - 2.921) .155 - .195* (3.937 - 4.953) .013 - .023 (0.330 - 0.584)
BSC
.067 (1.70)
.028 - .038 (0.711 - 0.965)
.135 - .165 (3.429 - 4.191)
* MEASURED AT THE SEATING PLANE
T5 (TO-220) 0801
1963afd
26
LT1963A Series PACKAGE DESCRIPTION
FE Package 16-Lead Plastic TSSOP (4.4mm)
(Reference LTC DWG # 05-08-1663)
Exposed Pad Variation BB
3.58 (.141)
4.90 - 5.10* (.193 - .201) 3.58 (.141) 16 1514 13 12 1110 9
6.60 0.10 4.50 0.10
SEE NOTE 4
2.94 (.116) 0.45 0.05 1.05 0.10 0.65 BSC 2.94 6.40 (.116) (.252) BSC
RECOMMENDED SOLDER PAD LAYOUT
12345678 1.10 (.0433) MAX
0 - 8
4.30 - 4.50* (.169 - .177)
0.25 REF
0.09 - 0.20 (.0035 - .0079)
0.50 - 0.75 (.020 - .030)
0.65 (.0256) BSC
NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) 3. DRAWING NOT TO SCALE
0.195 - 0.30 (.0077 - .0118) TYP
0.05 - 0.15 (.002 - .006)
FE16 (BB) TSSOP 0204
4. RECOMMENDED MINIMUM PCB METAL SIZE FOR EXPOSED PAD ATTACHMENT *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.150mm (.006") PER SIDE
1963afd
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
27
LT1963A Series TYPICAL APPLICATION
Adjustable Current Source
R5 0.01
LT1963A-1.8 IN OUT SHDN GND FB
LOAD
VIN > 2.7V
+ C1
10F
R1 1k LT1004-1.2 R2 80.6k
R4 2.2k
R6 2.2k
C3 1F
R8 100k
R3 2k 2
+
1/2 LT1366
8 1 4
R7 470
3 NOTE: ADJUST R1 FOR 0A TO 1.5A CONSTANT CURRENT C2 3.3F
-
1963A TA04
RELATED PARTS
PART NUMBER LT1175 LT1185 LT1761 LT1762 LT1763 LT1764/ LT1764A LTC1844 LT1962 LT1964 LT1965 LT3020 LT3023 LT3024 LT3080/ LT3080-1 DESCRIPTION 500mA, Micropower, Negative LDO 3A, Negative LDO 100mA, Low Noise Micropower, LDO 150mA, Low Noise Micropower, LDO 500mA, Low Noise Micropower, LDO COMMENTS VIN: -20V to -4.3V, VOUT(MIN) = -3.8V, VDO = 0.50V, IQ = 45A, ISD 10A, DD, SOT-223, PDIP8 Packages VIN: -35V to -4.2V, VOUT(MIN) = -2.40V, VDO = 0.80V, IQ = 2.5mA, ISD <1A, TO220-5 Package VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 20A, ISD <1A ThinSOT Package VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 25A, ISD <1A, MS8 Package VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 30A, ISD <1A, S8 Package
3A, Low Noise, Fast Transient Response, VIN: 2.7V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD <1A, DD, TO220 Packages LDO 150mA, Very Low Drop-Out LDO 300mA, Low Noise Micropower, LDO 200mA, Low Noise Micropower, Negative LDO 1.1A, Low Noise, Low Dropout Linear Regulator 100mA, Low Voltage VLDO, VIN(MIN) = 0.9V Dual, 2x 100mA, Low Noise Micropower, LDO Dual, 100mA/500mA, Low Noise Micropower, LDO 1.1A, Parallelable, Low Noise, Low Dropout Linear Regulator VIN: 6.5V to 1.6V, VOUT(MIN) = 1.25V, VDO = 0.08V, IQ = 40A, ISD < 1A, ThinSOTPackage VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.27V, IQ = 30A, ISD <1A, MS8 Package VIN: -0.9V to -20V, VOUT(MIN) = -1.21V, VDO = 0.34V, IQ = 30A, ISD 3A, ThinSOT Package 290mV Dropout Voltage, Low Noise: 40VRMS, VIN: 1.8V to 20V, VOUT: 1.2V to 19.5V, stable with ceramic caps, TO-220, DDPak, MSOP and 3mm x 3mm DFN Packages VIN: 0.9V to 10V, VOUT(MIN) = 0.20, VDO = 0.15V, IQ = 120A, ISD <3A, DFN, MS8 Packages VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40A, ISD <1A, DFN, MS10 Packages VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60A, ISD <1A, DFN, TSSOP Packages 300mV Dropout Voltage (2-Supply Operation), Low Noise: 40VRMS, VIN: 1.2V to 36V, VOUT: 0V to 35.7V, current-based reference with 1-Resistor VOUT set; directly parallelable (no op amp required), stable with ceramic caps, TO-220, SOT-223, MSOP and 3mm x 3mm DFN Packages; "-1" version has integrated internal ballast resistor
1963afd
28 Linear Technology Corporation
(408) 432-1900 FAX: (408) 434-0507
LT 0708 REV D * PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 2005

▲Up To Search▲

Price & Availability of LT1963AEFE

	To Download LT1963AEFE Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .