General Description
HMC981 is an active bias controller that automatically adjusts the gate voltage of an external amplifier to achieve constant bias current. It can be used to bias any enhancement and depletion type amplifiers operating in Class-A regime with Drain voltages from 4V to 12V and drain currents up to 200mA, offering a complete biasing solution.

Features
   Automatic Gate voltage adjustment (No Calibration required)
   Supply Voltage: 4V to 12V
   Digital Voltage: 3.3V to 5V
   Controls both Enhancement and Depletion type devices
   Adjustable Drain Current up to 200mA
   Sink/Source Gate Current Capability
   Optional Internal negative voltage generation that can be disabled to use external negative rail
   Fast Enable/Disable
   Trigger-out Output for Daisy Chain Power-Up and Power-Down Sequencing

Typical Applications
• Microwave Radio & VSAT
• Military & Space
• Test Instrumentation
• Fiber Optic Modulator Driver Biasing
• CATV Laser Driver Biasing
• Cellular Base Station
• Wireless Infrastructure Equipment