REV. D

AD7476/AD7477/AD7478

–7–

PIN CONFIGURATION

TOP VIEW

(Not to Scale)

6

5

4

1

2

3

GND

CS

SDATA

SCLK

AD7476/

AD7477/

AD7478

PIN FUNCTION DESCRIPTIONS

Pin

No.

Mnemonic

Function

2GND

Analog Ground. Ground reference point for all circuitry on the AD7476/AD7477/AD7478. All analog

input signals should be referred to this GND voltage.

4

SCLK

Serial Clock. Logic input. SCLK provides the serial clock for accessing data from the part. This clock

input is also used as the clock source for the AD7476/AD7477/AD7478’s conversion process.

5

SDATA

Data Out. Logic output. The conversion result from the AD7476/AD7477/AD7478 is provided on

this output as a serial data stream. The bits are clocked out on the falling edge of the SCLK input. The

data stream from the AD7476 consists of four leading zeros followed by the 12 bits of conversion data,

which is provided MSB first; the data stream from the AD7477 consists of four leading zeros followed

by the 10 bits of conversion data, followed by two trailing zeros, which is also provided MSB first; the

data stream from the AD7478 consists of four leading zeros followed by the eight bits of conversion

data, followed by four trailing zeros, which is provided MSB first.

6

CS

Chip Select. Active low logic input. This input provides the dual function of initiating conversions on

the AD7476/AD7477/AD7478 and framing the serial data transfer.