Features and Benefits
- 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
The LTC1550/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.
The LTC1550/LTC1551 operate from single 4.5V to 6.5V supplies and draw typical quiescent currents of 4.25mA with a 5V supply. Each device includes a TTL compatible 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 components 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 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 16-pin SSOP.
- GaAs FET Bias Generators
- Negative Supply Generators
- Battery-Powered Systems
- Single Supply Applications
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.