AD5231

Data Sheet

Rev. D | Page 8 of 28

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

16

15

14

13

12

11

10

9

RDY

A

W

TOP VIEW

(Not to Scale)

AD5231

1

2

3

4

5

6

7

8

CLK

SDI

SDO

GND

T

O1

B

O2

CS

PR

WP

Figure 5. Pin Configuration

Table 4. Pin Function Descriptions

Pin No.

Mnemonic

Description

1

O1

Nonvolatile Digital Output 1. ADDR = 0x1, data bit position D0. For example, to store O1 high, the data bit

format is 0x310001.

2

CLK

Serial Input Register Clock Pin. Shifts in one bit at a time on positive clock edges.

3

SDI

Serial Data Input Pin. Shifts in one bit at a time on positive clock CLK edges. MSB loaded first.

4

SDO

Serial Data Output Pin. Serves readback and daisy-chain functions.

Command 9 and Command 10 activate the SDO output for the readback function, delayed by 24 or 25 clock

pulses, depending on the clock polarity before and after the data-word (see Figure 3, Figure 4, and Table 7).

In other commands, the SDO shifts out the previously loaded SDI bit pattern, delayed by 24 or 25 clock pulses

depending on the clock polarity (see Figure 3 and Figure 4). This previously shifted-out SDI can be used for

daisy-chaining multiple devices.

Whenever SDO is used, a pull-up resistor in the range of 1 kΩ to 10 kΩ is needed.

5

GND

Ground Pin. Logic ground reference.

6

able to sink 40 mA for 25 ms when storing data to EEMEM.

7

T

8

B

Terminal B of RDAC.

9

W

Wiper Terminal of RDAC. ADDR (RDAC) = 0x0.

10

A

Terminal A of RDAC.

11

Positive Power Supply Pin.

12

WP

Optional Write Protect Pin. When active low, WP prevents any changes to the present contents, except PR and

Instruction 1 and Instruction 8 and refreshes the RDAC register from EEMEM. Execute a NOP instruction before

13

PR

Optional Hardware Override Preset Pin. Refreshes the scratchpad register with current contents of the EEMEM

14

CS

Serial Register Chip Select Active Low. Serial register operation takes place when CS returns to logic high.

15

RDY

Ready. Active-high open-drain output. Identifies completion of Instructions 2, 3, 8, 9, 10, and PR.

16

O2

Nonvolatile Digital Output 2. ADDR = 0x1, data bit position D1. For example, to store O2 high, the data bit

format is 0x310002.