Data Sheet

AD7091R

Rev. 0 | Page 7 of 20

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Figure 3. Pin Configuration, 10-Lead LFCSP

Figure 4. Pin Configuration, 10-Lead MSOP

Table 5. Pin Function Descriptions

Pin No.

LFCSP

MSOP

Mnemonic

Description

1

1

GND. The typical recommended values are 10 µF and 0.1 µF.

2

2

Voltage Reference Input Output. Decouple this pin to GND. The typical recommended decoupling

capacitor value is 2.2 µF. The user can either access the internal 2.5 V reference or overdrive the

internal reference with an externally applied voltage. The reference voltage range for an externally

3

3

4

4

REGCAP

Decoupling Capacitor Pin for Voltage Output from Internal Regulator. This output pin should be

decoupled separately to GND using a 1 μF capacitor. The voltage at this pin is 1.8 V typical.

5

5

GND

Analog Ground. This pin is the ground reference point for all circuitry on the AD7091R. The analog

input signal should be referred to this GND voltage.

6

6

CONVST

Convert Start. Active low edge triggered logic input. The falling edge of CONVST places the track-

and-hold into hold mode and initiates a conversion.

7

7

CS

Chip Select. Active low logic input. The serial bus is enabled when CS is held low, and in this mode CS

is used to frame the output data on the SPI bus.

8

8

SCLK

Serial Clock. This pin acts as the serial clock input.

9

9

SDO

Serial Data Output. The conversion output data is supplied to this pin as a serial data stream. The bits

are clocked out on the falling edge of the SCLK input. The data is provided MSB first.

10

10

Logic Power Supply Input. The voltage supplied at this pin determines the operating voltage of the

recommended values are 10 µF and 0.1 µF. The voltage range of this pin is 1.65 V to 5.25 V.

11

N/A

EPAD

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

joints and for maximum thermal capability, solder the exposed pad to the substrate, GND.

NOTES

1. THE EXPOSED PAD IS NOT CONNECTED INTERNALLY.

FOR INCREASED RELIABILITY OF THE SOLDER JOINTS AND

FOR MAXIMUM THERMAL CAPABILITY, SOLDER THE EXPOSED

PAD TO THE SUBSTRATE, GND.

AD7091R

1

2

3

4

REGCAP

5

GND

9

SDO

8

SCLK

7

CS

6

CONVST

TOP VIEW

(Not to Scale)

REGCAP

GND

SDO

SCLK

CS

CONVST

1

2

3

4

5

10

9

8

7

6

AD7091R

TOP VIEW

(Not to Scale)