HMC981 v00.0611 ACTIVE BIAS CONTROLLERTypical ApplicationsFeatures Automatic Gate voltage adjustment (No Calibration • Microwave Radio & VSAT IP required) H • Military & Space Supply Voltage: 4V to 12V • Test Instrumentation Digital Voltage: 3.3V to 5V • Fiber Optic Modulator Driver Biasing Controls both Enhancement and Depletion type S - C • CATV Laser Driver Biasing devices R • Cel ular Base Station Adjustable Drain Current up to 200mA • Wireless Infrastructure Equipment Sink/Source Gate Current Capability LLE Optional Internal negative voltage generation that O can be disabled to use external negative rail R T Fast Enable/Disable N Trigger-out Output for Daisy Chain Power-Up and O Power-Down Sequencing S C IA B Functional DiagramGeneral Description HMC981 is an active bias control er that automatical y 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 excel ent bias stability over supply, temperature and process variations, and eliminates the required calibration procedures usual y employed to prevent RF performance degradation due to such variations. All data shown herein is taken with appropriate probes. Inf F or o m r p atio r n ifc ur e n , d ishe e d lbiv y e A r n y a alog n D d t evic o p es is la beclie o eved rd to ebre sa: H ccur iattti e tae M nd re ilicarbloew . H a o ve C wever, o n rp o For price, delivery, and to place orders: Analog Devices, Inc., responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other oration, 2 Elizabeth Drive, Chelmsford, MA 01824 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106 Phone: 978-250-3343 Fax: 978-250-3373 O rights of third parties that may result from its use. Specifications subject to change without notice. No P rd ho e ne r O : 7 n 81- -3li 2n 9 e a -47 t w 0 w 0 • O w rd .h e it r o tniltie n .c e ao t m 1 license is granted by implication or otherwise under any patent or patent rights of Analog Devices. www.analog.com Application Support: Pho Trademarks and registered trademarks are the property of their respective owners. ne: 978-250-33 A 4 p 3 o plica r a tio p n S p u s p @ po h rt itt : P ite ho . n c e o : 1m -800-ANALOG-D
