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LT1020 Micropower Regulator and Comparator
FEATURES
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DESCRIPTIO
40A Supply Current 125mA Output Current 2.5V Reference Voltage Reference Output Sources 1mA and Sinks 0.5mA Dual Output Comparator Comparator Sinks 10mA Dropout Detector 0.2V Dropout Voltage Thermal Limiting Available in SO Package
The LT1020 is a combination micropower positive regulator and free collector comparator on a single monolithic chip. With only 40A supply current, the LT1020 can supply over 125mA of output current. Input voltage range is from 4.5V to 36V and dropout voltage is 0.6V at 125mA. Dropout voltage decreases with lower load currents. Also included on the chip is a class B output 2.5V reference that can either source or sink current. A dropout detector provides an output current to indicate when the regulator is about to drop out of regulation. The dual output comparator can be used as a comparator for system or battery monitoring. For example, the comparator can be used to warn of low system voltage while the dropout detector shuts down the system to prevent abnormal operation. Frequency compensation of the comparator for amplifier applications can be obtained by adding external output capacitance. Dual output or positive and negative regulators can also be made. The 2.5V reference will source or sink current. This allows it to be used as a supply splitter or auxiliary output.
APPLICATI
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Battery Systems Battery Backup Systems Portable Terminals Portable Instruments
TYPICAL APPLICATI
5V Regulator
Dropout Voltage and Supply Current
1 10
LT1020
0.001F FB 11
+
10F GND 9
1M
+
10F
DROPOUT VOLTAGE (V)
VIN > 5.2V IQ = 40A
3
VIN
VOUT
2
5V
SUPPLY CURRENT (mA)
1M
1020 TA01
0.1
0.01 0.1
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1 10 1 100 OUTPUT CURRENT (mA) 0.1 1000
1020 TA02
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1
LT1020 ABSOLUTE AXI U RATI GS
Operating Temperature Range LT1020C ............................................. 0C to 100C LT1020I ........................................ - 40C to 100 C LT1020M ....................................... - 55C to 125C Lead Temperature (Soldering, 10 sec).................. 300C Input Voltage .......................................................... 36V NPN Collector Voltage ............................................ 36V PNP Collector Voltage.............................. Supply - 36V Output Short Circuit Duration ......................... Indefinite Power Dissipation.............................. Internally Limited Storage Temperature Range ................ - 65C to 150C
PACKAGE/ORDER I FOR ATIO
TOP VIEW NC VOUT VIN REF OUT COMP PNP COMP NPN +INPUT 1 2 3 4 5 6 7 14 NC DROPOUT 13 DETECTOR 12 SHUTDOWN 11 FEEDBACK CURRENT 10 LIMIT 9 GND 8 -INPUT
ORDER PART NUMBER LT1020CJ LT1020CN LT1020IJ LT1020IN LT1020MJ
J PACKAGE 14-LEAD CERAMIC DIP
N PACKAGE 14-LEAD PLASTIC DIP
TJMAX = 150C, JA = 80C/W (J) TJMAX = 110C, JA = 130C/W (N)
ELECTRICAL CHARACTERISTICS
PARAMETER Reference Reference Voltage Line Regulation Load Regulation Output Source Current Output Sink Current Temperature Stability Regulator Supply Current CONDITIONS
TJ = 25C
MIN 2.46 TYP 2.50 0.01 0.2 4 2 1 45 75 11 125 0.2 0.01 0.02 0.4 2.5 20 0.5 0.015 0.05 0.65 2.56 MAX 2.54 0.015 0.3 UNITS V %/V % mA mA % A A mA mA % %/V V V V A
4.5V VIN 36V 4.5V VIN 36V - 0.5mA IREF 1mA, VIN = 12V VIN = 5V VIN = 5V
Output Current Load Regulation Line Regulation Dropout Voltage Feedback Sense Voltage Dropout Detector Current
VIN = 6V, IOUT 100A VIN = 36V, IOUT 100A VIN = 12V, IOUT = 125mA (VIN - VOUT) 1V, VIN 6V (VIN - VOUT) 1V, VIN 6V 6V VIN 36V IOUT = 100A IOUT = 125mA VIN = 12V VOUT = - 0.05V, IOUT = 500A
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TOP VIEW NC 1 VOUT 2 VIN 3 REF OUT 4 COMP PNP 5 COMP NPN 6 +INPUT 7 NC 8 16 NC 15 DROPOUT DETECTOR 14 SHUTDOWN 13 CURRENT LIMIT 12 FEEDBACK 11 GND 10 -INPUT 9 NC
ORDER PART NUMBER LT1020CS LT1020IS
S PACKAGE 16-LEAD PLASTIC SOIC
TJMAX = 110C, JA = 150C/W
1 0.5
80 120 20
2.44 3
LT1020
ELECTRICAL CHARACTERISTICS
PARAMETER Regulator Feedback Bias Current Minimum Load Current Short-Circuit Current Comparator Offset Voltage Bias Current Offset Current Gain-NPN Pull-Down Common-Mode Rejection Power Supply Rejection Output Sink Current NPN Saturation Voltage Output Source Current Input Voltage Range Response Time Leakage Current (NPN) CONDITIONS
TJ = 25C
MIN TYP 15 1 300 30 3 15 4 10000 94 96 18 0.4 200 5 2 MAX 40 5 400 UNITS nA A mA mA mV nA nA V/ V dB dB mA V A V s A
VIN = 36V VIN = 36V Pins 9 and 10 Shorted, VIN = 4.5V 0V VCM 35V, VIN = 36V 0V VCM 35V, VIN = 36V 0V VCM 35V, VIN = 36V VOUT = 29V, RL = 20k 0V VCM 35V, VIN = 36V 4.5V VS 36V VIN = 4.5V IOUT = 1mA
3
7 40 15
2000 80 80 10 60 0
0.6 VIN - 1
ELECTRICAL CHARACTERISTICS
PARAMETER Reference Reference Voltage Line Regulation Load Regulation Output Source Current Output Sink Current Regulator Supply Current CONDITIONS 4.5V VIN 36V 4.5V VIN 36V - 0.5mA IREF 1mA, VIN = 12V VIN = 5V VIN = 5V VIN = 6V, IOUT 100A VIN = 36V, IOUT 100A VIN = 12V, IOUT = 125mA (VIN - VOUT) 1V, VIN 6V (VIN - VOUT) 1V, VIN 6V 6V VIN 36V IOUT = 100A IOUT = 125mA VIN = 12V VOUT = - 0.05V, IOUT = 500A VIN = 36V VIN = 36V Pins 9 and 10 Shorted, VIN = 4.5V 0V VCM 35V, VIN = 36V 0V VCM 35V, VIN = 36V (Note 1) 0V VCM 35V, VIN = 36V VOUT = 29V, RL = 20k
q q q q q q q q q q q q q q q q q q q q q q q
MIN 2.40
TYP 2.50 0.01 0.3
MAX 2.55 0.02 0.4
UNITS V %/V % mA mA A A mA mA % %/ V V V V A nA A mA mA mV nA nA V/ V
1 0.5 65 85 11 125 1 0.02 0.06 0.85 2.57 50 50 400 95 120 20
Output Current Load Regulation Line Regulation Dropout Voltage Feedback Sense Voltage Dropout Detector Current Feedback Bias Current Minimum Load Current Short-Circuit Current Comparator Offset Voltage Bias Current Offset Current Gain-NPN Pull-Down
2.38 3
2.5
2.5
300 30
15 1000
10 60 20
3
LT1020
ELECTRICAL CHARACTERISTICS
PARAMETER Comparator Common-Mode Rejection Power Supply Rejection Output Sink Current Output Source Current Input Voltage Range Leakage Current (NPN) CONDITIONS 0V VCM 35V, VIN = 36V 4.5V VIN 36V VIN = 4.5V (Note 2)
q q q q q
MIN 80 80 5 40 0
TYP
MAX
UNITS dB dB mA A V A
10 120 VIN - 1 8
VIN = 36V
q
The q denotes specifications which apply over the full operating temperature range.
Note 1: For 0V VCM 0.1V and T > 85C IBIAS(MAX) is 100nA. Note 2: For TA - 40C output ISINK(MIN) is 2.5mA.
TYPICAL PERFOR A CE CHARACTERISTICS
Regulator Load Regulation
0.3 PRELOAD = 100A
OUTPUT VOLTAGE CHANGE (%)
SUPPLY CURRENT (mA)
TJ = -55C 0.1 0 -0.1 -0.2 -0.3 0.1 TJ = 125C TJ = 25C
10
SHORT-CIRCUIT CURRENT (mA)
0.2
1 10 100 OUTPUT CURRENT (mA)
Dropout Voltage
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
VOUT = 100mV
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1
INPUT/OUTPUT DIFFERENTIAL (V)
0.1
0.01 0.1
1 100 10 1000 REGULATOR OUTPUT CURRENT (mA)
1020 G04
4
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1020 G01
Supply Current
100 TJ = -55C TO 125C
Regulator Short-Circuit Current
350 300 250 200 150 100 50 0 -50 CURRENT LIMIT TIED TO GROUND
1
0.1
1000
0.01 0.1
10 100 1000 1 REGULATOR OUTPUT CURRENT (mA)
1020 G02
-10
70 110 30 TEMPERATURE (C)
150
1020 G03
Dropout Voltage
1 DROPOUT DETECTOR = 5A
1
Dropout Voltage
I DROPOUT DETECTOR = 0.1% IOUT
0.1
0.1 I DROPOUT DETECTOR = 1% IOUT
0.01 0.1
0.01
1 100 10 1000 REGULATOR OUTPUT CURRENT (mA)
1020 G05
0.1
1 10 100 REGULATOR OUTPUT CURRENT (mA)
1020 G06
LT1020
TYPICAL PERFOR A CE CHARACTERISTICS
Dropout Detector Current
100
DROPOUT DETECTOR CURRENT (A) 1000
DROPOUT DETECTOR CURRENT (A)
MINIMUM LOAD CURRENT (A)
VDIFF = 500mV 10
1
0.1 VDIFF = 1V 0.01 10 100 REGULATOR OUTPUT CURRENT (mA) 1000
Regulator Ripple Rejection
70 65 IOUT = 100mA IOUT = 10mA
SUPPLY CURRENT (mA) 1 10
RIPPLE REJECTION (dB)
SUPPLY CURRENT (mA)
60 55 IOUT = 1mA 50 45 40 35 30 10 VIN = 100VDC, 1VP-P VOUT = 5V COUT = 10F
10k 100 1k RIPPLE FREQUENCY (Hz)
Reference Regulation
4
REFERENCE VOLTAGE CHANGE (mV)
3
INPUT BIAS CURRENT (nA)
2 1 0 -1 -2 -3 -4 -1.5 0.5 1.0 -1.0 -0.5 0 REFERENCE OUTPUT CURRENT (mA) 1.5
80 70 60 50 40 30 20 10 0 -1.0
FEEDBACK PIN CURRENT (nA)
UW
1020 G07 1020 G10
Dropout Detector Current
100
IOUT = 100mA 100 IOUT = 25mA
Regulator Minimum Load Current
10
10
IOUT = 5mA IOUT = 1mA
1
0 0.2 0.3 0.4 0.5 0.6 0.1 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G08
1 70 80 90 100 110 120 130 140 TEMPERATURE (C) 150
1020 G09
Supply Current
10
Supply Current at Dropout
TJ = -55C TO 125C IOUT = 100mA
IOUT = 100mA
1 IOUT = 10mA 0.1
IOUT = 10mA 0.1 IOUT = 1mA VOUT = 5V TJ = -55C TO 125C
IOUT = 1mA
100k
0.01
1 10 15 20 25 5 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G11
0.01
0.2 0.3 0.4 0.5 0.6 0.1 0 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G12
Comparator Input Bias Current
100 90 TJ = 125C TJ = 25C TJ = -55C
40 35 30 25 20 15 10 5 0
Feedback Pin Current
TJ = -55C
TJ = 25C
TJ = 125C
1020 G13
-0.6 0.6 -0.2 GND 0.2 COMMON-MODE VOLTAGE (V) REFERRED TO PIN 9 (GND)
1.0
1020 G14
0.1
100 1000 1 10 REGULATOR OUTPUT CURRENT (mA)
1020 G15
5
LT1020
TYPICAL PERFOR A CE CHARACTERISTICS
Regulator Thermal Regulation
OUTPUT VOLTAGE CHANGE (%)
0.1 VIN = 15V VOUT = 5V 0 5.5 5.0 VOUT = 5V
OUTPUT VOLTAGE (V)
-0.1
OUTPUT CURRENT (mA)
50
0 0 20 40 60 80 100 120 140 160 180 TIME (ms)
1020 G16
PI FU CTIO S
Pins 1, 14: No internal connection. Pin 2: Regulator Output. Main output, requires 10F output capacitor. Can be shorted to VIN or ground without damaging the device. Pin 3: Input Supply. Bypass with 10F capacitor. Must always be more positive than ground. Pin 4: Reference. 2.5V can source or sink current. May be shorted to ground or up to 5V. Voltages in excess of 5V can damage the device. Pin 5: Comparator PNP Output. Pull-up current source for the comparator. May be connected to any voltage from VIN to 36V more negative than VIN (operates below ground). Short-circuit protected. For example, if VIN is 6V then pin 5 will operate to - 30V. Pin 6: Comparator NPN Output. May be connected to any voltage from ground to 36V more positive than ground (operates above VIN). Short-circuit protected. Pins 7, 8: Comparator Inputs. Operates from ground to VIN - 1V. Comparator inputs will withstand 36V even with VIN of 0V. Pin 9: Ground. Pin 10: Current Limit. Connecting this pin to ground decreases the regulator current limit to 3mA minimum. Leave open when not used. Pin 11: Feedback. This is the feedback point of the regulator. When operating, it is nominally at 2.5V. Optimum source resistance is 200k to 500k. The feedback pin should not be driven below ground or more positive than 5V. Pin 12: Shutdown. Turns output off. Pin 13: Dropout Detector. This pin acts like a current source from VIN which turns on when the output transistor goes into saturation. The magnitude of the current depends on the magnitude of the output current and the input/output voltage differential. Pin current ranges from 5A to about 300A.
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LT1020 Turn-On Characteristic
4.5 4.0 3.5 3.0 RL = 500 2.5 2.0 0 0 1 2 5 6 3 4 INPUT VOLTAGE (V) 7 8 NO LOAD RL = 50
1020 G17
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LT1020
BLOCK DIAGRA W
REF OUT 4 10 CURRENT LIMIT 3 VIN PNP OUT NPN OUT 5 6 2 13 VOUT DROPOUT DETECTOR 7 8 9 GND
1020 BD
NONINVERTING INVERTING
APPLICATI
S I FOR ATIO
The LT1020 is especially suited for micropower system applications. For example, the comparator section of the LT1020 may be used as a battery checker to provide an indication of low battery. The dropout detector can shut down the system when the battery voltage becomes too low to regulate. Another type of system application for the LT1020 would be to generate the equivalent of split supplies from a single power input. The regulator section provides regulated output voltage and the reference, which can both source and sink current, is then an artificial system ground providing a split supply for the system. For many applications the comparator can be frequency compensated to operate as an amplifier. Compensation values for various gains are given in the data sheet. The comparator gain is purposely low to make it easier to frequency compensate as an amplifier. Two outputs are available on the comparator, the NPN output is capable of sinking 10mA and can drive loads connected to voltages in excess of the positive power supply. This is useful for driving switches or linear regulators from a higher input voltage. The PNP output, which is capable of sourcing 100A can drive loads below ground. It can be used to make negative regulators with the addition of an external pass transistor. Both outputs can be tied together to provide an output that swings from rail-to-rail for comparator or amplifier applications. Although it is not specified, the gain for the PNP output is about 500 to 1000.
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- +
REF 2.5V
11 FB
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If the PNP output is being used, to maximize the gain a 1A to 5A load should be placed upon the NPN output collector. This is easily done by connecting a resistor between the NPN collector and the reference output. (Providing this operating current to the NPN side increases the internal emitter base voltages and maximizes the gain of the PNP stage.) Without this loading on the NPN collector, at temperatures in excess of 75C, the gain of the PNP collector can decrease by a factor of 2 or 3. Reference Internal to the LT1020 is a 2.5V trimmed class B output reference. The reference was designed to be able to source or sink current so it could be used in supply splitting applications as well as a general purpose reference for external circuitry. The design of the reference allows it to source typically 4mA or 5mA and sink 2mA. The available source and sink current decreases as temperature increases. It is sometimes desirable to decrease the AC output impedance by placing an output capacitor on them. The reference in the LT1020 becomes unstable with large capacitive loads placed directly on it. When using an output capacitor, about 20 should be used to isolate the capacitor from the reference pin. This 20 resistor can be placed directly in series with the capacitor or alternatively the reference line can have 20 placed in series with it and then a capacitor to ground. This is shown in Figure 1. Other than placing large capacitive loads on the reference, no
7
LT1020
APPLICATI S I FOR ATIO
other precautions are necessary and the reference is stable with nominal stray capacitances.
REF 4 OUTPUT 20 OR 10F REF 4 20 OUTPUT
+
+
10F
1020 F01
Figure 1. Bypassing Reference
Overload Protection The main regulator in the LT1020 is current limited at approximately 350mA. The current limit is stable with both input voltage and temperature. A current limit pin, when strapped to ground, decreases the output current. This allows the output current to be set to a lower value than 250mA. The output current available with the current limit pin strapped to ground is not well controlled so if precise current limiting is desired it should be provided externally as is shown in some of the application circuits. If the device is overloaded for long periods of time, thermal shutdown turns the output off. In thermal shutdown, there may be some oscillations which can disturb external circuitry. A diode connected between the reference and feedback terminal provides hysteresis under thermal shutdown, so that the device turns on and off with about a 5 second period and there are no higher frequency oscillations. This is shown in Figure 2. This diode is recommended for most applications. Thermal shutdown temperature is set at approximately 145C.
VOUT LT1020 REF 4 * * DIODE ADDS FEEDBACK FB
2 0.001F 11
+
10F
1020 F02
Figure 2. Minimizing Oscillation in Thermal Shutdown
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Like most other IC regulators, a minimum load is required on the output of the LT1020 to maintain regulation. For most standard regulators this is normally specified at 5mA. Of course, for a micropower regulator this would be a tremendously large current. The output current must be large enough to absorb all the leakage current of the pass transistor at the maximum operating temperature. It also affects the transient response; low output currents have long recovery times from load transients. At high operating temperatures the minimum load current increases and having too low of a load current may cause the output to go unregulated. Devices are tested for minimum load current at high temperature. The output voltage setting resistors to the feedback terminal can usually be used to provide the minimum load current. Frequency Compensation The LT1020 is frequency compensated by a dominant pole on the output. An output capacitor of 10F is usually large enough to provide good stability. Increasing the output capacitor above 10F further improves stability. In order to insure stability, a feedback capacitor is needed between the output pin and the feedback pin. This is because stray capacitance can form another pole with the large value of feedback resistors used with the LT1020. Also, a feedback capacitor minimizes noise pickup and improves ripple rejection. With the large dynamic operating range of the output current, 10000:1, frequency response changes widely. Low AC impedance capacitors are needed to insure stability. While solid tantalum are best, aluminum electrolytics can be used but larger capacitor values may be needed. The CURRENT LIMIT pin allows one of the internal nodes to be rolled off with a 0.05F capacitor to ground. With this capacitor, lower values of regulator output capacitance can be used (down to 1F) for low (<20mA) output currents. Values of capacitance greater than 0.05F degrade the transient response, so are not recommended. If the CURRENT LIMIT pin is connected to GND, the current limit is decreased and only a 1F output capacitor is needed. When bypassing the reference, a 20 resistor must be connected in series with the capacitor.
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LT1020
TYPICAL APPLICATI
LOGIC
500k 5 6
LOGIC OUTPUT
LOGIC OUTPUT GOES LOW WHEN VOUT DROPS BY 100mV
Driving Logic with Dropout Detector
VIN > 5.2V IQ = 40A 3 VIN
LT1020
DROPOUT 500k TO 2M
3M
1020 TA04
Regulator with Improved Transient Response
7
VIN > 5.2V
3
VIN LT1020 GND 9
VOUT
2 0.001F 1M
FB
11 0.001F 22k 1M
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Regulator with Output Voltage Monitor
3 VIN
-
LT1020
VOUT
2
5V 0.001F 100k
+
8 REF 7 4
2.5V
11 FB GND 9 100k
+
10F
20k 1M
1020 TA03
5V Regulator
VOUT LT1020 2 0.001F FB 11 1M
1020 TA07
5V 1M
+
10F GND 9
+
10F
Compensating the Comparator As an Op Amp
+
5
5V
8
-
1M
6
+
AT AV = 100, SLEW RATE = 0.05V/s -6V/s
10F
R2 C2
1020 TA08
R1 C1
AV 1 10 100
R1 33 100 10k
C1 C2 0.1F 0.001F 0.047F - 0.002F -
R2 - 100k 10k
1020 TA05
9
LT1020
TYPICAL APPLICATI
VIN 2.2k
9 GND 8 -INPUT
1 Amp Low Dropout Regulator
3 VIN LT1020 GND 9 CL 10 0.01F FB 11 150* 100k VOUT 2 * 10k*
MJE2955 VOUT 5V 220F
100k
SEE LT1129 DATA SHEET FOR 700mA OUTPUT
Maintaining Lowest IQ at Dropout
3 2 0.001F 1M
VIN LT1020 GND 9
VOUT
11 DROPOUT FB 13 2N3904* 1M NC 1M
* TRANSISTOR USED BECAUSE OF LOW LEAKAGE CHARACTERISTICS
1020 TA11
2N2907 12VOUT 0.01F 190k 6
+
10F 50k
10
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Dual Output Regulator
VIN > 5.2V 3 VIN VOUT LT1020 REF OUT 4 COMP FB 11 NPN 6 100k 500k
2 500k 0.001F
5V
0.001F
+
5 COMP PNP +INPUT 7
+
10F
* FOR CURRENT LIMIT 1.5A MUST HAVE LOW ESR. SEVERAL 100F CAPACITORS CAN BE PARALLELED.
1020 TA06
0.001F 1M
500k
+
10F -5V REG 10mA
2N3904 51k -VIN
1020 TA09
Dual Output 150mA Regulator
VIN > 5.2V 9 GND 8 -INPUT
5V
3 VIN VOUT LT1020 REF OUT 4
2 500k 0.001F
5V
+
10F
5 COMP PNP +INPUT 7 0.001F 200k
COMP FB 11 NPN 6 100k 500k
+
10F
100k
+
10F -5V REG 150mA
2N3904 51k* 4.7k 0.0047F 51k* -VIN
1020 TA10
2N3904
* FOR TEMPERATURES GREATER THAN 70C, REDUCE 51k RESISTORS TO 15k. IQ WILL INCREASE.
Dual Output Positive Regulator
3 51k VIN VIN 12.3V 2
-
LT1020
VOUT
5V 0.001F 1M
+
+IN 7 -IN 8 REF 4
11 FB GND 9 5 1M
+
10F
1020 TA12
LT1020
TYPICAL APPLICATI
BATTERY INPUT
VIN > 5.2V IQ = 40A
* TRANSISTOR USED BECAUSE OF LOW LEAKAGE CHARACTERISTICS. TO TURN OFF THE OUTPUT OF THE LT1020, FORCE FB (PIN 11) > 2.5V.
VIN
3
9 5 6
* VOUT TURNS OFF AT DROPOUT. VOUT TURN ON WHEN: VIN x R2 = 2.5V R1 + R2
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3 VIN VIN
S
Battery Backup Regulator
VOUT 5V VOUT LT1020 GND 9 FB 11 50k 2 2
+
0.001F 1M 10F 11
VOUT LT1020 FB GND 9
VIN
3
MAIN POWER INPUT
INTERNAL PARASITIC DIODES OF LT1020 VOUT
1M
1020 TA13
5V Regulator with Shutdown
3
VIN LT1020
VOUT
2
+
0.001F 1M 500k
5V 10F NC 2N3904* LOGIC INPUT
GND 9
FB 11 100k
1M
1020 TA14
Turn-Off at Dropout
R1 1.5M 8 R2 1M
-
LT1020
VOUT
2
VOUT* 0.001F 1M
+
DROPOUT 13 7 1.5M 0.047F
FB REF 4
11 1M
+
10F
1M
1020 TA15
11
LT1020
TYPICAL APPLICATI
LT1020 GND 9 FB
100k 8
1.2k
7
ISC SENSE 0.03
MUST HAVE LOW ESR. SEVERAL 100F CAPACITORS CAN BE PARALLELED.
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7
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Current Limited 1 Amp Regulator
2.2k 0.5* VIN MJE2955 0.22F VOUT 2 11 270 100k * SETS CURRENT LIMIT BUT INCREASES DROPOUT VOLTAGE BY 0.5V. MUST HAVE LOW ESR. SEVERAL 100F CAPACITORS CAN BE PARALLELED.
1020 TA16
3 VIN
2N3906*
100k
+
VOUT 5V, 1A 220F
1 Amp Regulator with Precision Current Limit
VIN 12V 2.2k
+
100F MJE2955 4 LT1020 2 11 3 VOUT 5V 1A 220F
+
0.22F 100k
FB
6
5
9
1N4148
270
100k
RL
1020 TA17
Logic Output on Dropout
VIN 4 3
- +
6
LT1020 2 1M FB 5 9 13 11 1M 0.001F VOUT 5V
+
10F
1M VIN "DROPOUT" 0V TTL COMPATIBLE
1020 TA18
LT1020
TYPICAL APPLICATI
Charge Pump Voltage Doubler
1M 51k
VIN 1N5819 OR EQUIVALENT VOUT
8 0.0033F
- +
3 5 6 9 1M 22k 2N3904 10F
51k
+
7
VOUT (NL) 2VIN - 1V VOUT (5mA) 2VIN - 3V IQ 300A
+
VOUT (NL) - (VIN - 1V) VOUT (5mA) - (VIN - 3V) IQ 300A
+
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Charge Pump Negative Voltage Generator
VIN
1M 51k
8 0.0033F
- +
3 5 6 9 1M 22k 2N3904
7
+
10F -VOUT 1N5819 OR EQUIVALENT 20F
1020 TA19
51k
20F
1020 TA20
13
LT1020
TYPICAL APPLICATI
+
10F
+
10F 51k
* VIN MUST BE GREATER THAN THE BATTERY VOLTAGE PLUS 1.3V
7.5V TO 30V VIN 100F 3.3M 30k 2N3906 2N3904 TO VREF (PIN4) 1.8M 1M 2N2222 2N3904 1k 100k LT1020 COMPARATOR 2M 10k 4mH 3 VIN LT1020 VREF 30k 4 FB 11 0.01F 220k VOUT 2 VOUT 5V 100mA 22F SWITCHING REGULATOR OUTPUT POST REGULATOR
MAINTAINS LOW IQ (< 100A) FOR ALL INPUT VOLTAGES SWITCHER EFFICIENCY = 85% POST REGULATOR EFFICIENCY = 82% OVERALL EFFICIENCY = 70% SWITCHING REGULATOR OUTPUT = 2.5 x (1 + RA /RB). FOR A CLEAN OUTPUT FROM THE LINEAR REGULATOR SET TO VOUT + 1.2V
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50mA Battery Charger and Regulator
VIN*
2N2905 20k 8 220k 4 3 VIN VOUT LT1020 2.5V FB 7 9 11 1M
10F
+
- +
2
5V
+
1M 0.001F 10F
6V BATTERY
3.9
1020 TA21
Switching Preregulator for Wide Input Voltage Range
+
-
6
8
+
2M
7
RA 1.5M
220k RB 1M 0.001F
+
30k 100F
1020 TA22
REFERENCE 4 3 R35 42k Q19 Q54 Q55 Q14 Q25 Q38 Q52 C5 100pF Q42 Q24 Q29 Q40 Q43 125k Q44 Q31 C2 25pF Q30 R11 15k R7 6.8k Q60 R10 75k Q35 Q34 R8 100k Q36 Q49 R16 6k Q22 Q63 Q62 Q61 Q32 Q64 Q33 C3 10pF Q45 Q37 Q46 Q47 R32 2k Q48 R30 2k R31 10 Q17 Q18 Q21 R17 100 Q41 125k Q27 Q26 Q23 C1 10pF Q28 Q56 R22 30k R23 30k R24 390k Q39 Q51 R8 40k R19 40k C6 100pF R33 138.3k 47k Q58
11 FEEDBACK
VIN
R4 42k
SCHE ATIC DIAGRA W
LT1020
Q1
Q13
OUTPUT 2 13 DROPOUT DETECTOR
Q2 Q15 Q16 Q20
PNP OUTPUT
5
NPN OUTPUT
6
Q10
Q6
Q5
Q9
Q11
Q8
Q7
Q12
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.
100pF Q65 R5 3k 15k 28k R6 3k R38 20k R14 15k R15 80k R18 15k 60k 60k R26 15k R27 15k R28 2k R29 5 100pF 7 +INPUT -NPUT 8 12 SHUTDOWN 10 CURRENT LIMIT
R1 25
R36 60k
R2 50k
R37 110.8k
R3 50k
9 GND
1020 SS
W
15
LT1020
PACKAGE DESCRIPTIO
0.290 - 0.320 (7.366 - 8.128)
0.008 - 0.018 (0.203 - 0.457) 0.385 0.025 (9.779 0.635)
0 - 15 0.025 (0.635) RAD TYP 0.220 - 0.310 (5.588 - 7.874)
0.045 - 0.068 (1.143 - 1.727) 0.014 - 0.026 (0.360 - 0.660)
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP OR TIN PLATE LEADS.
0.300 - 0.325 (7.620 - 8.255)
0.130 0.005 (3.302 0.127) 0.015 (0.380) MIN
0.009 - 0.015 (0.229 - 0.381) +0.025 0.325 -0.015 +0.635 8.255 -0.381
(
)
0.125 (3.175) MIN
0.100 0.010 (2.540 0.254)
0.010 - 0.020 x 45 (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) 0 - 8 TYP
0.016 - 0.050 0.406 - 1.270
16
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7487
(408) 432-1900 q FAX: (408) 434-0507 q TELEX: 499-3977
U
Dimensions in inches (millimeters) unless otherwise noted. J Package 14-Lead Ceramic DIP
0.200 (5.080) MAX 0.015 - 0.060 (0.381 - 1.524) 0.005 (0.127) MIN
0.785 (19.939) MAX 14 13 12 11 10 9 8
0.100 0.010 (2.540 0.254)
0.125 (3.175) MIN
1
2
3
4
5
6
7
N Package 14-Lead Plastic DIP
0.045 - 0.065 (1.143 - 1.651) 0.770 (19.558) MAX 14 0.065 (1.651) TYP 0.075 0.015 (1.905 0.381) 0.018 0.003 (0.457 0.076) 1 2 3 4 5 6 7 13 12 11 10 9 8
0.260 0.010 (6.604 0.254)
S Package 16-Lead Plastic SOIC
0.386 - 0.394* (9.804 - 10.008) 16 15 14 13 12 11 10 9
0.228 - 0.244 (5.791 - 6.197)
0.150 - 0.157* (3.810 - 3.988)
1 0.053 - 0.069 (1.346 - 1.752)
2
3
4
5
6
7
8
0.004 - 0.010 (0.101 - 0.254)
0.014 - 0.019 (0.355 - 0.483)
0.050 (1.270) TYP
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm).
LT/GP 1193 5K REV B * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1993

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