MCP4011-103ESLASHMS datasheet(32/60 Pages) MICROCHIP

32 / 60 page

MCP4011/2/3/4

DS21978C-page 32

5.2.3

DECREMENT

This mode is achieved by initializing the U/D pin to a low

state (VIL) prior to achieving a low state (VIL) on the CS

pin. Subsequent rising edges of the U/D pin will

decrement the wiper setting toward terminal B. This is

shown in Figure 5-3.

After the wiper is decremented to the desired position,

the U/D pin should be forced low (VIL) and the CS pin

should be forced to VIH. This will ensure that

“unexpected” transitions on the U/D pin do not cause

the wiper setting to decrement. Driving the CS pin to

VIH should occur as soon as possible (within device

specifications) after the last desired increment occurs.

When the device voltage falls below the RAM retention

voltage of the device, the wiper state may be corrupted.

When the device returns to the operating range, the

wiper will be loaded with the default POR wiper setting.

After the CS pin is driven to VIH (from VIL), any other

serial command may immediately be entered.

FIGURE 5-3:

Decrement.

Note:

The wiper value will not underflow. That is,

once the wiper value equals 0x00,

subsequent decrement commands are

ignored.

U/D

Wiper

X-1

XX-2

X-3

X-4

VIH

VIL

MCP4011-103E/MS Datasheet(PDF) 32 Page - Microchip Technology