AD9901

REV. B

–4–

TTL/CMOS MODE FUNCTIONAL PIN DESCRIPTIONS

GROUND

Ground connections for AD9901. Connect

all grounds together and to low impedance

ground plane as close to the device as

possible.

Positive supply connection; nominally +5.0 V

for TTL operation.

BIAS

VCO INPUT

TTL compatible input; normally connected

to the VCO output signal. VCO INPUT and

REFERENCE INPUT are equivalent to one

another.

OUTPUT

The noninverted output. In TTL/CMOS

mode, the output swing is approximately

+3.2 V to +5 V.

be connected to ground through an external

OUTPUT

The inverted output. In TTL/CMOS mode,

the output swing is approximately +3.2 V to

+5 V.

REFERENCE

TTL compatible input, normally connected

INPUT

to the reference input signal. The VCO

INPUT and the REFERENCE INPUT are

equivalent.

REG

AD9901

R1

OUTPUT

R2

REFERENCE

OUTPUT

OUTPUT

VCO

INPUT

BIAS

R3

Figure 1. TTL Mode (Based on DIP Pinouts)

ECL MODE FUNCTIONAL PIN DESCRIPTIONS

Negative supply connection, nominally

–5.2 V for ECL operation.

BIAS

Connect to –5.2 V for ECL operation.

VCO INPUT

Inverted side of ECL compatible differential

input, normally connected to the VCO output

signal.

VCO INPUT

Noninverted side of ECL-compatible

differential input, normally connected to the

VCO output signal.

OUTPUT

The noninverted output. In ECL mode, the

output swing is approximately 0 V to –1.8 V.

GROUND

Ground connections for AD9901. Connect

all grounds together and to low-impedance

ground plane as close to the device as

possible.

OUTPUT

The inverted output. In ECL mode, the out-

put swing is approximately 0 V to –1.8 V.

REFERENCE

Noninverted side of ECL-compatible

INPUT

differential input, normally connected to the

reference input signal. The VCO INPUT and

the REFERENCE INPUT are equivalent to

one another.

REFERENCE

Inverted side of ECL-compatible differential

INPUT

input, normally connected to the reference

input signal. The

VCO INPUT and the

REFERENCE INPUT are equivalent.

REG

AD9901

R1

OUTPUT

R2

REFERENCE

INPUT

OUTPUT

VCO

INPUT

BIAS

R3

REFERENCE

INPUT

VCO

INPUT

Figure 2. ECL Mode (Based on DIP Pinouts)