AD7980

Data Sheet

Rev. F | Page 8 of 26

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

Figure 4. 10-Lead MSOP Pin Configuration

Figure 5. 10-Lead LFCSP Pin Configuration

Table 7. Pin Function Descriptions

Pin No.

Mnemonic

Description

MSOP

LFCSP

1

1

REF

AI

Reference Input Voltage. The REF range is from 2.4 V to 5.1 V. It is referred to the GND

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

2

2

VDD

P

Power Supply.

3

3

IN+

AI

Analog Input. It is referred to IN−. The voltage range, for example, the difference

4

4

IN−

AI

Analog Input Ground Sense. To be connected to the analog ground plane or to a remote

sense ground.

5

5

GND

P

Power Supply Ground.

6

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 device, chain, or CS mode. In CS mode,

it enables the SDO pin when low. In chain mode, the data should be read when CNV is high.

7

7

SDO

DO

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

8

8

SCK

DI

Serial Data Clock Input. When the device is selected, the conversion result is shifted out

by this clock.

9

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 16 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

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).

Not

applicable

0

EPAD

Not

applicable

Exposed Pad. Connect the exposed pad to GND. This connection is not required to meet

the electrical performances.

1

AI = analog input, DI = digital input, DO = digital output, and P = power.

VIO

10

SDI

9

SCK

8

SDO

7

CNV

6

AD7980

TOP VIEW

(Not to Scale)

1

REF

2

VDD

3

IN+

4

IN–

5

GND

10 VIO

9 SDI

8 SCK

7 SDO

6 CNV

AD7980

TOP VIEW

(Not to Scale)

NOTES

1. CONNECT THE EXPOSED PAD TO GND.

THIS CONNECTION IS NOT REQUIRED TO

MEET THE ELECTRICAL PERFORMANCES.