Datasheet

MAX5432–MAX5435
32-Tap, Nonvolatile, I
2
C, Linear, Digital
Potentiometers
10 ______________________________________________________________________________________
Command Byte
Use the command byte to select the destination of the
wiper data (nonvolatile or volatile memory registers)
and swap data between nonvolatile and volatile memo-
ry registers (see Table 2).
Data Byte
The MAX5432–MAX5435 use the first 5 bits (MSBs,
D7–D3) of the data byte to set the position of the wiper.
The last 3 bits (D2, D1, and D0) are don’t care bits (see
Table 2).
Command Descriptions
VREG: The data byte writes to the volatile memory reg-
ister and the wiper position updates with the data in the
volatile memory register.
NVREG: The data byte writes to the nonvolatile memory
register. The wiper position is unchanged.
NVREGxVREG: Data transfers from the nonvolatile
memory register to the volatile memory register (wiper
position updates).
VREGxNVREG: Data transfers from the volatile memory
register into the nonvolatile memory register.
V
DD
I
OL
= 3mA
I
OH
= 0mA
V
OUT
400pF
SDA
Figure 2. Load Circuit
REGISTER ADDRESS BYTE COMMAND BTYE DATA BYTE
123456789101112131415161718192021222324252627
SCL CYCLE
NUMBER
START
A6 A5 A4 A3 A2 A1 A0
N
O
P/
W
A
C
K
C7 C6 C5 C4 C3 C2 C1 C0
A
C
K
D7 D6 D5 D4 D3 D2 D1 D0
A
C
K
STOP
VREG
0101A2A1A00 00010001 D7D6D5D4D3XXX
NVREG
0101A2A1A00 00100001 D7D6D5D4D3XXX
NVREGxVREG
0101A2A1A00 01100001 D7D6D5D4D3XXX
VREGxNVREG
0101A2A1A00 01010001 D7D6D5D4D3XXX
Table 2. Command Byte Summary
SDA
START
CONDITION
SCL
S
STOP
CONDITION
P
Figure 3. Start and Stop Conditions
SDA
SCL
*SEE THE
Ordering Information/Selector Guide
FOR OTHER ADDRESS OPTIONS.
01
A0
MSB LSB
NOP/W ACK
0 1 0* 0*
Figure 4. Slave Address
X = Don’t care.