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

9

HMC980

v00.0312

Active BiAs controller

High current

pad number

Function

Description

interface schematic

22,23,24,25

26

VDrain

Drain voltage. should be connected to the supply termi-

nal of the external amplifier. a minimum 10 nF capacitor

has to be placed close to the external amplifier to

improve load regulation.

27

VGate

Gate Control pad for external amplifier. Connect to the

gate (base) of the external amplifier. in order to guar-

antee stability, a 2.2μF capacitor should be connected

between the gate (base) terminal of the external ampli-

fier and GnD as close to the amplifier as possible.

28

VneG

negative input to the chip. should be supplied with

CpoUt when negative voltage generator is enabled, or

connect to external Vss when negative voltage genera-

tor is enabled. Defaults to -2.5V. if a value different than

-2.5V required, please contact factory.

29

VG2

second gate control.

30

VG2_Cont

Control voltage of the second gate pad VG2. Use a

resistor divider between VDD and GnD to set the volt-

age. VG2 is typically 1.3V lower than the VG2Cont.