Rainbow Electronics ADC12281 - Manual (Page 4)

Pin Descriptions and Equivalent Circuits
(Continued)
Pin Symbol Equivalent Circuit Description
3 V
IN COM
Analog input common. Connect to a quiet point in
analog ground near the driving device. See Section
1.2.
5 V
A
Positive analog supply pin. Connect to a clean,
quiet voltage source of +5V. V
A
and V
D
should
have a common supply and be separately
bypassed with a 5 µF to 10 µF capacitor and a
0.1 µF chip capacitor.
4, 6 AGND
The ground return for the analog supply, AGND and
DGND should be connected together close to the
ADC12281 package. See Section 5.0.
13 V
D
Positive digital supply pin. Connect to a clean, quiet
voltage source of +5V. V
A
and V
D
should have a
common supply and be separately bypassed with a
5 µF to 10 µF capacitor and a 0.1 µF chip
capacitor.
9, 12 DGND
The ground return for the digital supply. AGND and
DGND should be connected together close to the
ADC12281 package. See Section 5.0.
21 V
D
I/O
The digital output driver supply pins. This pin can
be operated from a supply voltage of 3V to 5V, but
the voltage on this pin should never exceed the V
D
supply pin voltage. See Section 3.4.
20 DGND I/O
The ground return for the digital output drivers. This
pin should be returned to a point in the digital
ground that is removed from the other ground pins
of the ADC12281.
ADC12281
www.national.com 4