For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824

Phone: 978-250-3343

Fax: 978-250-3373

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Application Support: Phone: 978-250-3343 or apps@hittite.com

10

HMC980

v00.0312

Active BiAs controller

High current

pad number

Function

Description

interface schematic

31

VGateFB

Control pad for VGateFB. Float VGateFB when a

depletion mode transistor is biased. selects the mode

of operation along with VneGFB pad.

32

VneGFB

Feedback (Control) pad for negative Voltage Genera-

tor Charge pump. Float to activate the negative voltage

generator / short to GnD to disable the negative voltage

generator.

33

VreF

1.44V reference voltage.

34

VDiG

3.3V-5V Digital Bias supply pad. Connect supply volt-

age to this pad with appropriate filtering.

37

Cp_oUt

negative voltage generator charge pump output. nega-

tive voltage generator requires a flying capacitor, a

reservoir capacitor and two diodes to operate.

38

Cp_VDD

Bias supply for negative voltage generator. Connect

supply voltage with appropriate filtering. Cp_VDD

supply voltage should be same as VDD.