LTC1550/LTC1551 Low Noise, Switched Capacitor Regulated Voltage Inverters FEATURES DESCRIPTION n The LTC 1550/LTC1551 are switched capacitor charge Regulated Negative Voltage from a Single pump voltage inverters which include internal linear post- Positive Supply n regulators to minimize output ripple. Output voltages are Low Output Ripple: Less Than 1mV Typ P-P n fixed at 4.1V, with ripple voltages typically below 1mV . High Charge Pump Frequency: 900kHz Typ P-P n The LTC1550 is also available in an adjustable output Small Charge Pump Capacitors: 0.1F n voltage version. The LTC1550/LTC1551 are ideal for use Requires Only Four External Capacitors n as bias voltage generators for GaAs transmitter FETs in Fixed 4.1V or Adjustable Output n portable RF and cellular telephone applications. Shutdown Mode Drops Supply Current to < 1A n High Output Current: Up to 10mA, V = 5V CC The LTC1550/LTC1551 operate from single 4.5V to 6.5V n Output Regulation: 5% supplies and draw typical quiescent currents of 4.25mA n Available in SO-8 and 16-Lead SSOP with a 5V supply. Each device includes a TTL compatible Shutdown pin which drops supply current to 0.2A typi- U cally. The LTC1550 Shutdown pin is active low (SHDN), APPLICATIONS while the LTC1551 Shutdown pin is active high (SHDN). n GaAs FET Bias Generators Only four external components are required: an input bypass n Negative Supply Generators capacitor, two 0.1F charge pump capacitors and a filter n Battery-Powered Systems capacitor at the linear regulator output. The adjustable LTC1550 n Single Supply Applications requires two additional resistors to set the output voltage. The LTC1550/LTC1551 will supply up to 10mA output current with a 5V supply, while maintaining guaranteed output regulation of 5%. The fixed voltage LTC1550/LTC1551 are available in S0-8 plastic packages. The adjustable LTC1550 is available in a , LTC and LT are registered trademarks of Linear Technology Corporation. 16-pin SSOP. TYPICAL APPLICATION 4.1V Generator with 1mV Noise V Output Noise and Ripple P-P OUT 1 8 V CC SHDN SENSE 2 7 V CP CC OUT + 4.7F C CP LTC1551 C 0.1F V IN 3 6 OUT + C1 GND AC COUPLED 4 5 2mV/DIV V C1 OUT FERRITE BEAD V = 4.1V OUT I = 5mA LOAD C OUT C L 10F 0.1F C1 1550/51 F01 0.1F 10s/DIV 1550/51 TA02 1 + U ULTC1550/LTC1551 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage ......................................................... 7V Commercial Temperature Range ................. 0C to 70C Output Voltage ................................ 0.3V to (V 14V) Extended Commercial Operating CC Total Voltage, V to CP ............................................. 14V Temperature Range (Note 3) .............. 40C to 85C CC OUT Input Voltage (SHDN Pin) ........... 0.3V to (V + 0.3V) Industrial Temperature Range ................ 40C to 85C CC Input Voltage (REG Pin)............................ 0.3V to 12V Storage Temperature Range ................ 65C to 150C Output Short-Circuit Duration .............................. 30 sec Lead Temperature (Soldering, 10 sec)................. 300C PACKAGE/ORDER INFORMATION TOP VIEW ORDER ORDER NC 1 16 V CC PART NUMBER PART NUMBER TOP VIEW + C1 2 15 SHDN SHDN* 1 8 SENSE NC 3 14 REG LTC1550CS8-4.1 LTC1550CGN V 2 7 CP CC OUT V 4 13 SENSE OUT LTC1551CS8-4.1 LTC1550IGN + C1 3 6 GND C1 5 12 ADJ V 4 5 C1 OUT PGND 6 11 CP OUT AGND 7 10 NC S8 PACKAGE GN PART MARKING 8-LEAD PLASTIC SO NC 8 9 NC *SHDN FOR LTC1550, SHDN FOR LTC1551 1550 GN PACKAGE T = 150C, = 150C/ W JMAX JA 16-LEAD PLASTIC SSOP T = 150C, = 150C/ W JMAX JA Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS V = 4.5V to 6.5V, C1 = C2 = 0.1F, C = 10F, T = 25C unless otherwise specified. (Note 3) CC OUT A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Supply Voltage CC (LTC1550CGN/LTC1550IGN) l 2.7 6.5 V (LTC1550CS8-4.1/LTC1551CS8-4.1) l 4.5 6.5 V V Reference Voltage l 1.24 V REF I Supply Current V = 5V, V = V (LTC1550) or GND (LTC1551) l 4.25 7 mA S CC SHDN CC V = 5V, V = GND (LTC1550) or V (LTC1551) l 0.2 10 A CC SHDN CC f Internal Oscillator Frequency 900 kHz OSC V REG Output Low Voltage I = 1mA, V = 5V l 0.1 0.8 V OL REG CC I REG Sink Current V = 0.8V, V = 5V l 715 mA REG REG CC V SHDN Input High Voltage V = 5V l2V IH CC V SHDN Input Low Voltage V = 5V l 0.8 V IL CC I SHDN Input Current V = V l 0.1 1 A IN SHDN CC t Turn-On Time I = 10mA 1 ms ON OUT V Output Regulation 2.7V V 6.5V, 0 I 5mA l 1.575 1.5 1.425 V OUT CC OUT (LTC1550CGN/LTC1550IGN) 2.8V V 6.5V, 0 I 10mA l 1.575 1.5 1.425 V CC OUT 3.5V V 6.5V, 0 I 20mA l 1.575 1.5 1.425 V CC OUT V Output Regulation 2.7V V 6.5V, 0 I 5mA l 2.1 2.0 1.9 V OUT CC OUT (LTC1550CGN/LTC1550IGN) 3.1V V 6.5V, 0 I 10mA l 2.1 2.0 1.9 V CC OUT 3.75V V 6.5V, 0 I 20mA l 2.1 2.0 1.9 V CC OUT 2 U W U W U WW