View LTC1551L_277286.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Final Electrical Specifications
LTC1550L/LTC1551L Low Noise, Switched Capacitor Regulated Voltage Inverters
September 1998
FEATURES
s s s s s s s s
DESCRIPTION
The LTC(R)1550L/LTC1551L are switched capacitor charge pump voltage inverters which include internal linear postregulators to minimize output ripple. The LTC1550L output voltages include -4.1V, -2.5V and -2V with ripple voltages typically below 1mVP-P. The LTC1550L is also available in an adjustable output voltage version. The LTC1550L/LTC1551L are ideal for use as bias voltage generators for GaAs transmitter FETs in portable RF and cellular telephone applications. The LTC1550L/LTC1551L operate from single 2.7V to 5.5V supplies and draw typical quiescent currents of 3.5mA with a 5V supply. Each device includes a TTL compatible Shutdown pin which drops supply current to 0.2A typically. The LTC1550L Shutdown pin is active low (SHDN), while the LTC1551L Shutdown pin is active high (SHDN). Only four external components are required: an input bypass capacitor, two 0.1F charge pump capacitors and a filter capacitor at the linear regulator output. The adjustable LTC1550L/LTC1551L require two additional resistors to set the output voltage. The LTC1550L/LTC1551L will supply up to 20mA (depending on VCC to VOUT range), while maintaining guaranteed output regulation of 2.5%. Both fixed voltage and adjustable LTC1550L/LTC1551L are available in 8-lead MSOP and SO plastic packages: the adjustable LTC1550L is also available in a 16-pin SSOP with the REG pin.
VOUT Output Noise and Ripple
s
s
Regulated Negative Voltage from a Single Positive Supply Low Output Ripple: Less Than 1mV P-P Typ High Charge Pump Frequency: 900kHz Typ Small Charge Pump Capacitors: 0.1 F Requires Only Four External Capacitors Fixed -4.1V, -2.5V, -2V or Adjustable Output Shutdown Mode Drops Supply Current to <1 A High Output Current: Up to 20mA (Depending on VCC to V OUT Range) Output Regulation: 2.5% Over Line, Load and Temperature Available in 8-Lead MSOP, 8-Lead Narrow SO and 16-Lead Narrow SSOP
APPLICATIONS
s s s s
GaAs FET Bias Generators Negative Supply Generators Battery-Powered Systems Single Supply Applications
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
3.6V 1 2 SHDN VCC C1+ VOUT REG CPOUT 8 7 CCP 0.1F R1 10k POWER VALID
+
2.2F CIN
LTC1550L-2 3 4 GND C1 - 6 5
VOUT AC COUPLED 2mV/DIV
C1 0.1F
COUT 10F
VOUT = -2V ILOAD = 5mA CL 0.1F
1550L/51L TA01
Figure 1. - 2V Generator with 1mVP-P Noise
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.
U
U
+
U
5s/DIV
1550L/51L TA01a
1
LTC1550L/LTC1551L
ABSOLUTE MAXIMUM RATINGS
Supply Voltage ...................................................... 5.5V Output Voltage ............................. 0.3V to (VCC - 10.5V) Total Voltage, VCC to CPOUT ......................................... 10.8V Input Voltage (SHDN Pin) ........... - 0.3V to (VCC + 0.3V) Input Voltage (REG Pin).............................. - 0.3V to 6V Output Short-Circuit Duration .............................. 30 sec
PACKAGE/ORDER INFORMATION
TOP VIEW SHDN* VCC C1+ VOUT 1 2 3 4 8 7 6 5 REG (ADJ*) CPOUT GND C1 -
SHDN* 1 VCC 2 C1+ 3 VOUT 4
MS8 PACKAGE 8-LEAD PLASTIC MSOP *SHDN FOR LTC1550L, SHDN FOR LTC1551L *FOR ADJUSTABLE VERSION TJMAX = 150C, JA = 200C/W
ORDER PART NUMBER LTC1550LCMS8 LTC1550LCMS8-2 LTC1550LCMS8-2.5 LTC1550LCMS8-4.1 LTC1551LCMS8 LTC1551LCMS8-4.1
*SHDN FOR LTC1550L, SHDN FOR LTC1551L *FOR ADJUSTABLE VERSION TJMAX = 150C, JA = 135C/W
MS8 PART MARKING LTEG LTGR LTFV LTEH LTFQ LTFT
Consult factory for Military grade parts and additional voltage options.
ELECTRICAL CHARACTERISTICS
VCC = 2.7V to 5.25V, C1 = C2 = 0.1F, COUT = 10F, TA = 25C unless otherwise specified. (Note 3)
PARAMETER Supply Voltage (Adjustable, Fixed -2V) (Fixed -2.5V) (Fixed - 4.1V) VREF Reference Voltage VREF Reference Voltage (VCC - VOUT) Line Regulation IS Supply Current SYMBOL VCC CONDITIONS
q q q
VCC = 5V, ADJ = GND, VREF = -VOUT IOUT = 0mA, 2.7V VCC 5.25V VCC = 5V, VSHDN = VCC (LTC1550L) or GND (LTC1551L) q VCC = 5V, VSHDN = GND (LTC1550L) or VCC (LTC1551L) q
2
U
U
W
WW
U
W
(Note 1)
Commercial Temperature Range ................. 0C to 70C Extended Commercial Operating Temperature Range (Note 3) .............. - 40C to 85C Industrial Temperature Range ................ - 40C to 85C Storage Temperature Range ................ - 65C to 150C Lead Temperature (Soldering, 10 sec)................. 300C
TOP VIEW 8 7 6 5 REG (ADJ*) CPOUT GND C1 -
NC 1 C1+ 2
TOP VIEW 16 VCC 15 SHDN 14 REG 13 NC 12 ADJ 11 CPOUT 10 NC 9 NC
NC 3 VOUT 4 C1- 5
S8 PACKAGE 8-LEAD PLASTIC SO
PGND 6 AGND 7 NC 8
GN PACKAGE 16-LEAD PLASTIC SSOP TJMAX = 150C, JA = 150C/W
ORDER PART NUMBER LTC1550LCS8 LTC1550LCS8-2 LTC1550LCS8-2.5 LTC1550LCS8-4.1 LTC1551LCS8 LTC1551LCS8-4.1
ORDER PART NUMBER LTC1550LCGN LTC1550LIGN GN PART MARKING 1550L 1550LI
MIN 2.7 3.05 4.5
TYP
MAX 5.25 5.25 5.25
UNITS V V V V mV/V mA A
1.225 2.5 3.65 0.2 7 10
LTC1550L/LTC1551L
ELECTRICAL CHARACTERISTICS
VCC = 2.7V to 5.25V, C1 = C2 = 0.1F, COUT = 10F, TA = 25C unless otherwise specified. (Note 3)
SYMBOL fOSC VOL IREG VIH VIL IIN tON VOUT PARAMETER Internal Oscillator Frequency REG Output Low Voltage REG Sink Current SHDN Input High Voltage SHDN Input Low Voltage SHDN Input Current Turn-On Time Output Regulation (LTC1550L/LTC1551L) Output Regulation (LTC1550L/LTC1550L-2/ LTC1551L) Output Regulation (LTC1550L/LTC1550L-2.5/ LTC1551L) Output Regulation (LTC1550L/LTC1551L) Output Regulation (LTC1550L/LTC1551L) Output Regulation (LTC1550L/LTC1550L-4.1) (LTC1551L/LTC1551L-4.1) Output Regulation (LTC1550L/LTC1551L)) Output Short-Circuit Current Output Ripple Voltage CONDITIONS IREG = 1mA, VCC = 5V VREG = 0.8V, VCC = 5V VCC = 5V VCC = 5V VSHDN = VCC (All LTC1550L Versions) VSHDN = VCC (All LTC1551L Versions) IOUT = 10mA 2.7V VCC 5.25V, 0 IOUT 5mA 2.8V VCC 5.25V, 0 IOUT 10mA 3.5V VCC 5.25V, 0 IOUT 20mA 2.7V VCC 5.25V, 0 IOUT 5mA 3.1V VCC 5.25V, 0 IOUT 10mA 3.75V VCC 5.25V, 0 IOUT 20mA 3.05V VCC 5.25V, 0 IOUT 5mA 3.45V VCC 5.25V, 0 IOUT 10mA 4.1V VCC 5.25V, 0 IOUT 20mA 3.45V VCC 5.25V, 0 IOUT 5mA 3.85V VCC 5.25V, 0 IOUT 10mA 4.5V VCC 5.25V, 0 IOUT 20mA 3.9V VCC 5.25V, 0 IOUT 5mA 4.2V VCC 5.25V, 0 IOUT 10mA 4.85V VCC 5.25V, 0 IOUT 20mA 4.5V VCC 5.25V, 0 IOUT 5mA 4.75V VCC 5.25V, 0 IOUT 10mA 4.8V VCC 5.25V, 0 IOUT 5mA 5.1V VCC 5.25V, 0 IOUT 10mA VOUT = 0V, VCC = 5.25V
q q q q q q q q q q q q q q q q q q q q q q q q q q
MIN
TYP 900 0.1 10
MAX 0.8
UNITS kHz V mA V V A A ms V V V V V V V V V V V V V V V V V V V mA mV
4 2
VOUT
VOUT
VOUT
VOUT
VOUT
- 1.537 - 1.537 - 1.537 - 2.05 - 2.05 - 2.05 - 2.562 - 2.562 - 2.562 - 3.075 - 3.075 - 3.075 - 3.587 - 3.587 - 3.587 - 4.203 - 4.203 - 4.613 - 4.613
0.1 5 1 - 1.5 - 1.5 - 1.5 - 2.0 - 2.0 - 2.0 - 2.5 - 2.5 - 2.5 - 3.0 - 3.0 - 3.0 - 3.5 - 3.5 - 3.5 - 4.1 - 4.1 - 4.5 - 4.5 80 1
0.8 1 20 - 1.463 - 1.463 - 1.463 - 1.95 - 1.95 - 1.95 - 2.438 - 2.438 - 2.438 - 2.925 - 2.925 - 2.925 - 3.413 - 3.413 - 3.413 - 3.998 - 3.998 - 4.388 - 4.388 200
VOUT ISC VRIPPLE
The q denotes specifications which apply over the specified temperature range. Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to ground unless otherwise specified. All typicals are given at TA = 25C.
Note 3: The LTC1550LC/LTC1551LC are guaranteed to meet specified performance from 0C to 70C and are designed, characterized and expected to meet these extended temperature limits, but are not tested at - 40C and 85C. The LTC1550LI is guaranteed to meet the extended temperature limits.
PIN FUNCTIONS
SHDN: Shutdown (TTL Compatible). This pin is active low (SHDN) for the LTC1550L and active high (SHDN) for the LTC1551L. When this pin is at VCC (GND for LTC1551L), the LTC1550L operates normally. When SHDN is pulled low (high for LTC1551L), the LTC1550L enters shutdown mode. In shutdown, the charge pump stops, the output collapses to 0V, and the quiescent current drops typically to 0.2A. The SHDN pin for the LTC1550L is a high impedance input and has no internal pull-up. The user must supply a resistor or current source pull-up to default the LTC1550L into normal operation. The SHDN pin for the LTC1551L has an internal 5A typical pull-down that defaults the LTC1551L into normal operation.
U
U
U
3
LTC1550L/LTC1551L
PIN FUNCTIONS
VCC: Power Supply. VCC requires an input voltage between 2.7V and 5.25V. Certain combinations of output voltage and output load current may place additional restrictions on the required input voltage. Consult the Electrical Characteristics table and Typical Performance Characteristics for guaranteed test points. The difference between the input voltage and output should not exceed 10.5V or damage to the chip may occur. VCC must be bypassed directly to PGND (GND for 8-pin packages) with at least a 0.1F capacitor placed in close proximity to the chip. A 1F or larger low ESR bypass capacitor is recommended to minimize noise and ripple at the output. A surface mount ceramic capacitor is recommended. C1 +: C1 Positive Input. Connect a 0.1F capacitor between C1 + and C1 -. VOUT: Negative Voltage Output. This pin must be bypassed with a 4.7F or larger capacitor to ensure regulator loop stability. LTC recommends at least 10F to achieve the specified output ripple. The output capacitor should be a moderate ESR capacitor, and not a very low ESR capacitor, as the zero in the feedback loop (formed by the ESR and the output capacitor) provides phase lead to the linear regulator feedback loop. Using very low ESR output capacitors will result in the output oscillating. A low ESR 0.1F capacitor is recommended in parallel with the main output capacitor to minimize high frequency spikes at the output. The ground connection for the output capacitor should connect directly to the VCC and CPOUT bypass capacitors, as well as to the GND of the LTC1550L/ LTC1551L. LTC recommends a separate trace for the VOUT capacitor ground connection to minimize noise. C1 -: C1 Negative Input. Connect a 0.1F capacitor from C1 + to C1 -. GND: Ground. Connect to a low impedance ground. A ground plane will help minimize regulation errors. CPOUT: Negative Charge Pump Output. This pin requires a 0.1F storage capacitor to ground. In order to achieve ripple on the output voltage of less than 1mV, the ground connection for the CPOUT capacitor must tie directly to the bottom of the VCC bypass capacitor and at the GND pin of the LTC1550L/LTC1551L. This minimizes the AC current path for the charge pump. REG: This is an open-drain output that pulls low when the output voltage is within 5% of the set value. It will sink 4mA to ground with a 5V supply. The external circuitry must provide a pull-up or REG will not swing high. The voltage at REG may exceed VCC and can be pulled up to 6V above ground without damage. For the LTC1550L adjustable voltage version, the REG pin is only available in the 16-lead GN package. ADJ (for adjustable versions): This is the feedback point for the external resistor divider string. Connect a divider string from GND to VOUT with the divided tap connected to ADJ. Note that the resistor string needs to be connected "upside-down" from a negative regulator. See the Applications Information section for hook-up details. GN PACKAGE ONLY PGND: Power Ground. Connect to a low impedance ground. PGND should be connected to the same potential as AGND. AGND: Analog Ground. Connect to a low impedance ground. AGND should be connected to a ground plane to minimize regulation errors. NC: No Internal Connection.
RELATED PARTS
PART NUMBER LT 1054 LTC1261 LTC1429 LTC1550/LTC1551
(R)
DESCRIPTION Switched-Capacitor Voltage Converter with Regulator Switched-Capacitor Regulated Voltage Inverter Clock-Synchronized Switched-Capacitor Voltage Inverter Low Noise, Switched-Capacitor Regulated Voltage Inverters
4
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com
U
U
U
COMMENTS 100mA Switched-Capacitor Converter Selectable Fixed Output Voltages Synchronizable Up to 2MHz System Clock 900kHz Charge Pump, 1mVP-P Ripple
15501li LT/TP 0998 4K * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1998

▲Up To Search▲

Price & Availability of LTC1551L

	To Download LTC1551L Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .