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13

HMC980LP4E

ACTIVE BIAS CONTROLLER

HIGH CURRENT

v01.0911

Pin Number

Function

Description

Interface Schematic

11

VNEGFB

Feedback (Control) pin for Negative Voltage Generator

Charge Pump. Float to activate the negative voltage

generator / Short to GND to disable the negative voltage

generator.

12

VGATEFB

Control pin for VGATEFB. Float VGATEFB when a

depletion mode transistor is biased. Selects the mode

of operation along with VNEGFB pin.

13

VG2_CONT

Control voltage of the second gate pin VG2. Use a

resistor divider between VDD and GND to set the volt-

age. VG2 is typically 1.3V lower than the VG2CONT

14

VG2

Second gate control.

15

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.

16

VGATE

Gate Control pin 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.

17, 18

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.