Datasheet

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.
+V
S
Positive supply connection; nominally +5.0 V
for TTL operation.
BIAS Connect to +V
S
(+5 V) for TTL operation.
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.
R
SET
External R
SET
connection. The current
through the R
SET
resistor is equal to the maxi-
mum full-scale output current. R
SET
should
be connected to ground through an external
resistor in TTL mode. I
SET
= 0.47 V/R
SET
=
I
LOAD
(max).
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
R
SET
AD9901
R1
OUTPUT
R2
+V
S
+V
S
REFERENCE
OUTPUT
OUTPUT
+V
S
VCO
INPUT
BIAS
+V
S
+V
S
R3
Figure 1. TTL Mode (Based on DIP Pinouts)
ECL MODE FUNCTIONAL PIN DESCRIPTIONS
–V
S
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.
R
SET
External R
SET
connection. The current
through the R
SET
resistor is equal to the maxi-
mum full-scale output current. R
SET
should
be connected to –V
S
through an external
resistor in ECL mode. I
SET
= 0.47 V/R
SET
=
I
LOAD
(max).
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
R
SET
AD9901
R1
OUTPUT
R2
–V
S
REFERENCE
INPUT
OUTPUT
VCO
INPUT
BIAS
R3
REFERENCE
INPUT
–V
S
–V
S
VCO
INPUT
–V
S
Figure 2. ECL Mode (Based on DIP Pinouts)