REV. B

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a

Ultrahigh Speed

Phase/Frequency Discriminator

AD9901

GENERAL DESCRIPTION

The AD9901 is a digital phase/frequency discriminator capable

of directly comparing phase/frequency inputs up to 200 MHz.

Processing in a high speed trench-oxide isolated process, com-

bined with an innovative design, gives the AD9901 a linear

detection range, free of indeterminate phase detection zones

common to other digital designs.

With a single +5 V supply, the AD9901 can be configured to

operate with TTL or CMOS logic levels; it can also operate

with ECL inputs when operated with a –5.2 V supply. The

open-collector outputs allow the output swing to be matched to

post-filtering input requirements. A simple current setting resis-

tor controls the output stage current range, permitting a reduc-

tion in power when operated at lower frequencies.

FEATURES

Phase and Frequency Detection

ECL/TTL/CMOS Compatible

Linear Transfer Function

No “Dead Zone”

MIL-STD-883 Compliant Versions Available

APPLICATIONS

Low Phase Noise Reference Loops

Fast-Tuning “Agile” IF Loops

Secure “Hopping” Communications

Coherent Radar Transmitter/Receiver Chains

A major feature of the AD9901 is its ability to compare

phase/frequency inputs at standard IF frequencies without

prescalers. Excessive phase uncertainty which is common with

standard PLL configurations is also eliminated. The AD9901

provides the locking speed of traditional phase/frequency dis-

criminators, with the phase stability of analog mixers.

The AD9901 is available as a commercial temperature range

device, 0

°C to +70°C, and as a military temperature device,

–55

°C to +125°C. The commercial versions are packaged in a

14-lead ceramic DIP and a 20-lead PLCC.

The AD9901 Phase/Frequency Discriminator is available in

versions compliant with MIL-STD-883. Refer to the Analog

Devices Military Products Databook or current AD9901/883B

data sheet for specifications.

FUNCTIONAL BLOCK DIAGRAM

OSCILLATOR

INPUT

FLIP-FLOP

DQ

Q

REFERENCE

INPUT

FLIP-FLOP

DQ

Q

XOR

OUTPUT

OUTPUT

REFERENCE

INPUT

OSCILLATOR

INPUT

OSCILLATOR

FREQUENCY

DISCRIMINATOR

FLIP-FLOP

DQ

Q

S

REFERENCE

FREQUENCY

DISCRIMINATOR

FLIP-FLOP

DQ

Q

R

PHASE-LOCKED LOOP

LOW-

PASS

FILTER

1/N

VCO

AD9901

REFERENCE

INPUT

OSCILLATOR

OUTPUT

OPTIONAL 1/N PRESCALER

TYPICAL OF DIGITAL PLLs

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

World Wide Web Site: http://www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 1999