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

7

HMC980

v00.0312

Active BiAs controller

High current

Pad Descriptions

pad number

Function

Description

interface schematic

1,12,13,20,21,

35

GnD

these pads and the die bottom must be connected to a

high quality rF/DC ground.

2

alM

over/under current alarm. provides an active high signal

(VDiG) if the quiescent bias exceed the upper threshold

or drops below the lower threshold.

19

triGoUt

trigger out signal. Generates a hiGh (3.3V) signal when

the active bias system stabilizes. this signal can be

used to trigger next device (enaBle) if more than one

hMC980 is used in a daisy chain.

3

alMtrG

Dummy alarm trigger signal to create test alarm when

taken hiGh (3.3V). Defaults to loW (GnD) when left

floating.

4

en

enable pad. Bias control loop is enabled when Ven

is hiGh(VDiG). if left floating, Ven defaults to hiGh

(enabled).

5,6

s1,s0

Control pads for internal switch resistance. if left float-

ing, default to hiGh.

refer to table-1 in application notes for recommended

settings.

7,8,9,10,11

VDD

Bias supply pad. Connect supply voltage to this pad

with appropriate filtering.

14

FiXBias

a high precision (e.g. 0.5%, ±25 ppm tCr) 10K resistor

to ground is recommended for good bias accuracy.