HMC981 Datasheet, PDF (1/18 Pages) Hittite Microwave Corporation – ACTIVE BIAS CONTROLLER

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Typical Applications
• Microwave Radio & VSAT
• Military & Space
• Test Instrumentation
• Fiber Optic Modulator Driver Biasing
• CATV Laser Driver Biasing
• Cellular Base Station
• Wireless Infrastructure Equipment
HMC981
ACTIVE BIAS CONTROLLER
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
Functional Diagram
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.
HMC981 achieves excellent bias stability over supply,
temperature and process variations, and eliminates
the required calibration procedures usually employed
to prevent RF performance degradation due to such
variations.
All data shown herein is taken with appropriate probes.
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For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
2 Elizabeth Drive, Chelmsford, MA 01824 Phone: [phone] Fax: [phone]
Order On-line at www.hittite.com