Datasheet

MAX5432–MAX5435
32-Tap, Nonvolatile, I
2
C, Linear, Digital
Potentiometers
______________________________________________________________________________________ 11
Nonvolatile Memory
The internal EEPROM consists of a 5-bit nonvolatile
register that retains the value written to it before the
device is powered down. The nonvolatile register is
programmed with the zeros at the factory. Wait a mini-
mum of 12ms after writing to NVREG before sending
another command.
Power-Up
Upon power-up, the MAX5432–MAX5435 load the data
stored in the nonvolatile memory register into the
volatile memory register, updating the wiper position
with the data stored in the nonvolatile memory register.
This initialization period takes 20µs.
Standby
The MAX5432–MAX5435 feature a low-power standby
mode. When the device is not being programmed, it
goes into standby mode and current consumption is
typically 0.5µA.
SDA
DATA STABLE,
DATA VALID
CHANGE OF
DATA ALLOWED
SCL
Figure 5. Bit Transfer
1
SCL
START
CONDITION
SDA
289
CLOCK PULSE FOR
ACKNOWLEDGMENT
ACKNOWLEDGE
NOT ACKNOWLEDGE
Figure 6. Acknowledge
S
SLAVE
ADDRESS
0
A
D15
D14 D13
D12
D11 D10
D9
D8
COMMAND BYTE
A
P
ACKNOWLEDGE FROM
MAX5432–MAX5435
ACKNOWLEDGE FROM
MAX5432–MAX5435
NOP/W
COMMAND BYTE IS STORED ON
RECEIPT OF STOP CONDITION
Figure 7. Command Byte Received
S
SLAVE ADDRESS
0
A
D15
D14 D13
D12
D11 D10
D9
D8
COMMAND BYTE
ACKNOWLEDGE FROM
MAX5432–MAX5435
ACKNOWLEDGE FROM
MAX5432–MAX5435
NOP/W
HOW COMMAND BYTE AND DATA BYTE MAP
INTO MAX5432–MAX5435's REGISTERS
A
DATA BYTE
A
P
D7
D6 D5 D4
D3
X
XX
BYTE
1
ACKNOWLEDGE FROM
MAX5432–MAX5435
Figure 8. Command and Single Data Byte Received