Data Sheet

AD7690

Rev. C | Page 7 of 24

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

Figure 5. 10-Lead MSOP Pin Configuration

Figure 6. 10-Lead LFCSP Pin Configuration

Table 6. Pin Function Descriptions

Pin No.

Mnemonic

Description

1

REF

AI

Reference Input Voltage. The REF range is from 0.5 V to VDD. It is referred to the GND pin. This

pin should be decoupled closely to the pin with a 10 μF capacitor.

2

VDD

P

Power Supply.

3

IN+

AI

Differential Positive Analog Input.

4

IN−

AI

Differential Negative Analog Input.

5

GND

P

Power Supply Ground.

6

CNV

DI

Convert Input. This input has multiple functions. On its leading edge, it initiates the conversions

and selects the interface mode of the part, chain or CS mode. In CS mode, the SDO pin is

enabled when CNV is low. In chain mode, the data should be read when CNV is high.

7

SDO

DO

Serial Data Output. The conversion result is output on this pin. It is synchronized to SCK.

8

SCK

DI

Serial Data Clock Input. When the part is selected, the conversion result is shifted out by this clock.

9

SDI

DI

Serial Data Input. This input provides multiple features. It selects the interface mode of the ADC

as follows:

Chain mode is selected if SDI is low during the CNV rising edge. In this mode, SDI is used as a

data input to daisy-chain the conversion results of two or more ADCs onto a single SDO line.

The digital data level on SDI is output on SDO with a delay of 18 SCK cycles.

CS mode is selected if SDI is high during the CNV rising edge. In this mode, either SDI or CNV

can enable the serial output signals when low. If SDI or CNV is low when the conversion is

complete, the busy indicator feature is enabled.

10

VIO

P

Input/Output Interface Digital Power. Nominally at the same supply as the host interface (1.8 V,

2.5 V, 3 V, or 5 V).

EPAD

Exposed Pad. The exposed pad is not connected internally. For increased reliability of the solder

joints, it is recommended that the pad be soldered to the ground plane.

VIO

10

SDI

9

SCK

8

SDO

7

CNV

6

AD7690

TOP VIEW

(Not to Scale)

1

REF

2

VDD

3

IN+

4

IN–

5

GND

10 VIO

9SDI

8SCK

7SDO

6 CNV

TOP VIEW

(Not to Scale)

AD7690

NOTES

1. THE EXPOSED PAD IS NOT CONNECTED

INTERNALLY. FOR INCREASED RELIABILITY OF

THE SOLDER JOINTS, IT IS RECOMMENDED THAT

THE PAD BE SOLDERED TO THE GROUND PLANE.