MCP4023 Microchip Technology, MCP4023 Datasheet - Page 33

• Manufacturer Part Number: MCP4023
• Description: Low-Cost NV Digital POT with WiperLock Technology
• Manufacturer: Microchip Technology

5.2.4
This mode is achieved by initializing the U/D pin to a
low state (V
CS pin. Subsequent rising edges of the U/D pin
decrement the wiper setting (toward terminal B). This is
shown in
After the wiper is decremented to the desired position,
the U/D pin should remain high (V
CS pin is raised to V
EEPROM. Therefore, if the device voltage is lowered
below the RAM retention voltage of the device, once
the device returns to the operating range, the wiper will
be loaded with this wiper setting (stored in the
EEPROM).
FIGURE 5-4:
© 2006 Microchip Technology Inc.
WiperLock™ Technology
Figure
IL
DECREMENT WITH WRITING
WIPER SETTING TO EEPROM
) prior to achieving a low state (V
5-4.
IH
EEPROM
, the wiper value is written to the
Decrement with Writing Wiper Setting to EEPROM.
Wiper
U/D
CS
Note: If WiperLock technology enabled, wiper will not change.
IH
V
). Then when the
IL
V
IL
X
X
IL
1
) on the
X-1
X
2
X-2
X
3
To ensure that “unexpected” transitions on the U/D pin
do not cause the wiper setting to decrement, the U/D
pin should be driven low (V
V
after the last desired increment occurs.
After the CS pin is driven to V
serial commands are ignored until the EEPROM write
cycle (t
X-3
IH
X
Note:
as soon as possible (within device specifications)
4
WC
X-4
X
) completes.
The wiper value will not underflow. That is,
once the wiper value equals 0x00,
subsequent decrement commands are
ignored.
t
WC
WiperLock Technology Enable
WiperLock Technology Disable
MCP4021/2/3/4
X-4
5
IL
) and the CS pin forced to
IH
6
(from V
V
DS21945E-page 33
V
IH
IH
IL
), all other