Datasheet

© 2006 Microchip Technology Inc. DS21978C-page 37
MCP4011/2/3/4
5.2.8 HIGH-VOLTAGE DECREMENT 2
(FOR MCP402X COMPATIBILITY)
This mode is achieved by initializing the U/D
pin to the
low state (V
IL
) prior to driving the CS pin to V
IHH
.
Subsequent rising edges of the U/D pin decrement the
wiper setting toward terminal B. Set the U/D
pin to a
high state (V
IH
) prior to forcing the CS pin to V
IH
. This
is shown in Figure 5-8.
After the CS
pin is driven to V
IH
(from V
IL
), any other
serial command may immediately be entered.
FIGURE 5-8: High-Voltage Decrement 2 (For MCP402X Compatibility).
Note: This command allows compatibility with
the MCP402X family, which supports
updating of the non-volatile wiper setting
with the WiperLock Technology feature.
Note: The wiper value will not underflow. That is,
once the wiper value equals 0x00,
subsequent decrement commands are
ignored.
U/D
CS
Wiper
1 2 3 4
X-1
X
X-2 X-3 X-4
V
IHH
V
DD
V
IH
V
IH
5
6
V
IH
V
IL