Rainbow Electronics MAX5499 - Manual (Page 16)

MAX5494–MAX5499
10-Bit, Dual, Nonvolatile, Linear-Taper
Digital Potentiometers
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Copy NV Register to Wiper Register
The “copy NV register to wiper register” (C1, C0 = 11)
restores the wiper position to the current value stored in
the NV register. Figure 11 shows how to copy data from
NV register 1 to wiper register 1.
Standby Mode
The MAX5494–MAX5499 feature a low-power standby
mode. When the device is not being programmed, it
enters into standby mode and supply current drops to
0.6µA (typ).
Nonvolatile Memory
The internal EEPROM consists of a nonvolatile register
that retains the last value stored prior to power-down.
The nonvolatile register is programmed to midscale at
the factory. The nonvolatile memory is guaranteed for
50 years for wiper data retention and up to 200,000
wiper write cycles.
Power-Up
Upon power-up, the MAX5494–MAX5499 load the data
stored in the nonvolatile wiper register into the wiper
register, updating the wiper position with the data
stored in the nonvolatile wiper register.
Applications Information
The MAX5494–MAX5499 are intended for circuits
requiring digitally controlled adjustable resistance,
such as LCD contrast control (where voltage biasing
adjusts the display contrast), or programmable filters
with adjustable gain and/or cutoff frequency.
ACTION
0 0 1 0 0 0 0 1
1 2 3 4 5 6 7 8
SCLK
DIN
CS
C1 C0 RA1 RA0
WRITE NV
REGISTER 1
(DEVICE IS BUSY)
t BUSY
Figure 10. Copy Wiper Register 1 to NV Register 1
ACTION
0 0 1 1 0 0 0 1
1 2 3 4 5 6 7 8
SCLK
DIN
CS
C1 C0 RA1 RA0
WIPER REGISTER
1 UPDATED
Figure 11. Copy NV Register 1 to Wiper Register 1