High Current, Active Bias Controller Data Sheet HMC980LP4E FEATURES FUNCTIONAL BLOCK DIAGRAM HMC980LP4E Automatic gate voltage adjustment (no calibration) Supply voltage (5 V to 16.5 V) Bias enhancement or depletion mode devices Adjustable drain current up to 1.6 A Sink or source gate current VDD 1 18 VDRAIN Optional internal negative voltage generation GATE Fast enable/disable 2 VDD 17 VDRAIN CONTROL TRIGOUT output for daisy chain S0 3 CONTROL 16 VGATE Power-up and power-down sequencing + BLOCK Overcurrent/undercurrent alarm with hysteresis 15 VNEG S1 4 BAND GAP 2 24-lead, 4 mm 4 mm LFCSP package: 16 mm EN 5 14 VG2 NEGATIVE VOLTAGE APPLICATIONS GENERATOR 13 VG2 CONT ALM 6 Microwave radio and very small aperture terminals (VSATs) PACKAGE Military and space BASE Test instrumentation GND Fiber optic modulator driver biasing CATV laser driver biasing Figure 1. Cellular base station Wireless infrastructure equipment GENERAL DESCRIPTION The HMC980LP4E is an active bias controller that can automati- The HMC980LP4E allows stable RF amplifier biasing over cally adjust the gate voltage of an external amplifier to achieve supply, temperature, and process variations, and eliminates the constant drain current. Using an integrated controller, the required calibration procedures usually employed to prevent HMC980LP4E allows safe power-up/power-down, and RF performance degradation due to variations in amplifier disable/enable of an external amplifier, ensuring the safe drain current. powering of the amplifier. The HMC980LP4E can be used to The HMC980LP4E is housed in an RoHS compliant bias any enhancement or depletion type Class A amplifier 4 mm 4 mm LFCSP leadless package with an exposed operating with drain voltages from 5 V to 16.5 V and drain backside pad to improve thermal characteristics. currents up to 1.6 A, thus offering a complete biasing solution. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. Tel: 781.329.4700 2021 Analog Devices, Inc. All rights reserved. No license is granted by implication or otherwise under any patent or patent rights of Analog Technical Support www.analog.com Devices. Trademarks and registered trademarks are the property of their respective owners. 24 FIXBIAS CP VDD 7 CP OUT 8 23 ALMH 22 ISET VDIG 9 VREF 10 21 ALML 20 ISENSE VNEGFB 11 19 TRIGOUT VGATEFB 12 20370-001HMC980LP4E Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Controlling Depletion Mode RF Amplifiers .......................... 14 Applications ...................................................................................... 1 Supply Voltages .......................................................................... 14 Functional Block Diagram .............................................................. 1 Supply Sequencing ..................................................................... 15 General Description ......................................................................... 1 Drain Voltage Output ................................................................ 15 Revision History ............................................................................... 3 Setting the Target Drain Current ............................................. 15 Specifications .................................................................................... 4 MOSFET Series Resistance ....................................................... 15 Electrical Specifications ............................................................... 4 Enable Input ................................................................................ 16 Absolute Maximum Ratings ........................................................... 5 VG2 Voltage Adjustment .......................................................... 16 Thermal Resistance ...................................................................... 5 Self Protection ............................................................................. 16 Electrostatic Discharge (ESD) Ratings ...................................... 5 Overcurrent/Undercurrent Alarm .......................................... 17 ESD Caution.................................................................................. 5 Negative Voltage Generator ..................................................... 18 Pin Configuration and Function Descriptions ............................ 6 Disabling the Internal Negative Voltage Generator .............. 18 Interface Schematics .................................................................... 8 Changing the Default VNEG Voltage ..................................... 19 Typical Performance Characteristics ............................................. 9 Changing the VGATE Threshold Voltage ............................. 20 Theory of Operation ...................................................................... 13 Design Examples ........................................................................ 21 Overview ...................................................................................... 13 Enhancement Mode Operation ............................................... 22 Power-Up and Power-Down .................................................... 13 Recommended HMC980LP4E Circuits .................................. 22 Negative Voltage Generator ..................................................... 13 Daisy-Chain Operation ............................................................. 23 VGATE Output Control Loop ................................................. 13 Higher Drain Current Applications ........................................ 23 Stability ........................................................................................ 13 Reducing External Component Count ................................... 25 Secondary Gate Control ............................................................ 13 Evaluation Board Circuit............................................................... 26 External Amplifier Power Sequencing .................................... 13 Outline Dimensions ....................................................................... 28 Overcurrent/Undercurrent Alarm .......................................... 13 Ordering Guide .......................................................................... 28 Self Protection ............................................................................. 13 Applications Information .............................................................. 14 Rev. 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