Pin Configuration And Function Descriptions; Changes To Pin Function Descriptions - Analog Devices AD5235 Manual

AD5235

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 CLK Serial Input Register Clock. Shifts in one bit at a time on positive clock edges.
2 SDI Serial Data Input. Shifts in one bit at a time on positive clock CLK edges. MSB loads first.
3 SDO Serial Data Output. Serves readback and daisy-chain functions.
Commands 9 and 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 2, Figure 3, 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 2 and Figure 3). 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.
4 GND Ground Pin, Logic Ground Reference.
5 V Negative Supply. Connect to 0 V for single-supply applications. If V
SS
35 mA for 30 ms when storing data to EEMEM.
6 A1 Terminal A of RDAC1.
7 W1 Wiper terminal of RDAC1. ADDR(RDAC1) = 0x0.
8 B1 Terminal B of RDAC1.
9 B2 Terminal B of RDAC2.
10 W2 Wiper terminal of RDAC2. ADDR(RDAC2) = 0x1.
11 A2 Terminal A of RDAC2.
12 V Positive Power Supply.
DD
13 WP Optional Write Protect. When active low, WP prevents any changes to the present contents, except PR strobe.
CMD_1 and COMD_8 refresh the RDAC register from EEMEM. Execute a NOP instruction before returning to WP
high. Tie WP to V
14 PR Optional Hardware Override Preset. Refreshes the scratchpad register with current contents of the EEMEM
register. Factory default loads midscale 512
at the logic high transition. Tie PR to V
15 CS Serial Register Chip Select Active Low. Serial register operation takes place when CS returns to logic high.
16 RDY Ready. Active-high open-drain output. Identifies completion of Instructions 2, 3, 8, 9, 10, and PR.
CLK
1
SDI
2
SDO
3
AD5235BRU
GND
4
V
TOP VIEW
5
SS
(Not to Scale)
A1
6
W1
7
B1
8
Figure 4. Pin Configuration
, if not used.
DD
until EEMEM is loaded with a new value by the user. PR is activated
10
, if not used.
DD
Rev. B | Page 8 of 28
16 RDY
15 CS
PR
14
WP
13
V
12
DD
A2
11
10 W2
9 B2
is used in dual supply, it must be able to sink
SS