LTC1551 Datasheet | Linear Technology

LTC1550/LTC1551 Low Noise, Switched Capacitor Regulated Voltage Inverters Features s s s s s s s s s s DESCRIPTION The LTC®1550/LTC1551 are switched capacitor charge pump voltage inverters which include internal linear postregulators to minimize output ripple. Output voltages are fixed at - 4.1V, with ripple voltages typically below 1m VP-P. The LTC1550 is also available in an adjustable output voltage version. The LTC1550/LTC1551 are ideal for use as bias voltage generators for Ga As transmitter FETs in portable RF and cellular telephone applications. The LTC1550/LTC1551 operate from single 4.5V to 6.5V supplies and draw typical quiescent currents of 4.25m A with a 5V supply. Each device includes a TTL patible Shutdown pin which drops supply current to 0.2µA typically. The LTC1550 Shutdown pin is active low (SHDN), while the LTC1551 Shutdown pin is active high (SHDN). Only four external ponents are required: an input bypass capacitor, two 0.1µF charge pump capacitors and a filter capacitor at the linear regulator output. The adjustable LTC1550 requires two additional resistors to set the output voltage. The LTC1550/LTC1551 will supply up to 10m A 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 16-pin SSOP. Regulated Negative Voltage from a Single Positive Supply Low Output Ripple: Less Than 1m VP-P Typ High Charge Pump Frequency: 900k Hz Typ Small Charge Pump Capacitors: 0.1µF Requires Only Four External Capacitors Fixed - 4.1V or Adjustable Output Shutdown Mode Drops Supply Current to < 1µA High Output Current: Up to 10m A, VCC = 5V Output Regulation: 5% Available in SO-8 and 16-Lead SSOP U APPLICATIONS s s s s Ga As FET Bias Generators Negative Supply Generators Battery-Powered Systems Single Supply Applications , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION -...