ADI HMC980LP4ETR

HMC980LP4E is an active bias controller that can automatically adjust the gate voltage of an external amplifer to achieve constant bias current. With an integrated controller, HMC980LP4E achieves safe power on/off, disable/enable and automatic supply sequencing ensuring the safety of the external amplifer. It can be used to bias any enhancement and depletion type amplifer operating in Class-A regime with drain voltages (VDRAIN) from 5V to 16.5V and drain currents (IDRAIN) up to 1.6 A, offering a complete biasing solution. HMC980LP4E 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. The HMC980LP4E is housed in an RoHS compliant 4x4 mm QFN leadless package with an exposed backside pad to improve thermal characteristics.

All amplifers require stable quiescent current to operate at their specifcations. Many amplifers in the market require external biasing to achieve stable quiscent current. HMC980LP4E is a fully integrated biasing solution for such amplifers. With an internal feedback, the automatic gate voltage control achieves constant quiescent bias through the amplifer under bias, independent of temperature and amplifer threshold variations. The quiescent current is adjusted with a resistor connected externally. The HMC980LP4E employs an integrated control circuitry to manage safe power-up and power-down sequencing of the targeted amplifer. The HMC980LP4E can provide auto-bias solution to virtually any amplifer in the market (both enhancement and depletion type) with a quiescent current of up to 1.6A and a supply voltage of up to 16.5V. The HMC980LP4E has an integrated negative voltage generator to create negative voltages required to drive depletion mode amplifers. If an external negative supply is already available or an enhancement mode device is targeted, the negative voltage generator can be disabled. The HMC980LP4E achieves excellent bias stability over supply and temperature variations. The gate control can both sink and source current (±4 mA) which is required to compensate for charging gate current of the amplifer over input power variations. The HMC980LP4E also generates a second gate voltage VG2. VG2 can be adjusted through a resistor divider connected to VDD for the amplifers which require second gate voltage. The HMC980LP4E ensures safety of the external amplifer during turn on/off by automatically adjusting the sequence of VDRAIN, VGATE and VG2 outputs. The HMC980LP4E has a built-in over-under current alarm feature. If a fault conditions arises (either under or over current) an alarm signal is generated (ALM, active HIGH). The current alarm signal provided in HMC980LP4E does not affect the operation of the controller. It is included for monitoring purposes where a system level protection can be implemented with external control circuitry. The HMC980LP4E employs S0, S1 pins to control RDS_ON resistance of the internal switch between VDD and VDRAIN. The HMC980LP4E has a built-in self protection feature to protect itself against short circuit conditions at the VDRAIN output. The HMC980LP4E has also a built-in VNEG fault protection feature to protect both itself and the amplifer under bias against short circuit conditio

• Automatic Gate voltage adjustment (No Calibration required)
• Supply Voltage (5V to 16.5V)
• Bias both Enhancement or Depletion type devices
• Adjustable Drain Current up to 1.6 A
• Sink or source gate current
• Internal negative voltage generation
• Can be disabled to use external negative rail
• Fast Enable/Disable
• Trigger-out Output for Daisy Chain
• Power-Up and Power-Down Sequencing
• Over/Under Current Alarm with built-in hystresis
• 24 Lead 4mmx4mm QFN Package: 16mm2

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