Data Sheet

AD7608

Rev. A | Page 13 of 32

Pin No.

Type

12F11F

1

Mnemonic

Description

34

DI

REF SELECT

Internal/External Reference Selection Input. Logic input. If this pin is set to logic high then the

internal reference is selected and is enabled, if this pin is set to logic low then the internal reference

is disabled and an external reference voltage must be applied to the REFIN/REFOUT pin.

36, 39

P

REGCAP

Decoupling Capacitor Pins for Voltage Output from Internal Regulator. These output pins should be

decoupled separately to AGND using a 1 μF capacitor. The voltage on these output pins is in the

range of 2.5 V to 2.7 V.

42

REF

REFIN/

REFOUT

Reference Input/Reference Output. The on-chip reference of 2.5 V is available on this pin for external

use if the REF SELECT pin is set to a logic high. Alternatively, the internal reference can be disabled

by setting the REF SELECT pin to a logic low and an external reference of 2.5 V can be applied to this

input. See the Internal/External Reference section. Decoupling is required on this pin for both the

internal or external reference options. A 10 µF capacitor should be applied from this pin to ground

close to the REFGND pins.

43, 46

REF

REFGND

Reference Ground Pins. These pins should be connected to AGND.

44, 45

REF

REFCAPA,

REFCAPB

Reference Buffer Output Force/Sense Pins. These pins must be connected together and decoupled

to AGND using a low ESR 10 μF ceramic capacitor.

49, 51, 53,

55, 57, 59,

61, 63

AI

V1 to V8

Analog Inputs. These pins are single-ended analog inputs. The analog input range of these channels

is determined by the RANGE pin.

50, 52, 54,

56, 58, 60,

62, 64

AI/

GND

V1GND to

V8GND

Analog Input Ground Pins. These pins correspond to the V1 to V8 analog input pins. Connect all

analog input AGND pins to the AGND plane of a system.

1

Refers to classification of pin type; P denotes power, AI denotes analog input, REF denotes reference, DI denotes digital input, DO denotes digital output.