DESCRIPTION
The LTC®1550/LTC1551 are switched capacitor charge pump voltage inverters which include internal linear post regulators to minimize output ripple. Output voltages are fixed at – 4.1V, with ripple voltages typically below 1mVP-P. The LTC1550 is also available in an adjustable output voltage version. The LTC1550/LTC1551 are ideal for use as bias voltage generators for GaAs transmitter FETs in portable RF and cellular telephone applications.

FEATURES
■ Regulated Negative Voltage from a Single Positive Supply
■ Low Output Ripple: Less Than 1mVP-P Typ
■ High Charge Pump Frequency: 900kHz 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 10mA, VCC = 5V
■ Output Regulation: 5%
■ Available in SO-8 and 16-Lead SSOP

APPLICATIONS
■ GaAs FET Bias Generators
■ Negative Supply Generators
■ Battery-Powered Systems
■ Single Supply Applications