Datasheet

 2010 Microchip Technology Inc. DS22248A-page 21
MCP4901/4911/4921
4.2.4 SHUTDOWN MODE
The user can shut down the device by using a software
command. During Shutdown mode, most of the internal
circuits, including the output amplifier, are turned off for
power savings. The serial interface remains active,
thus allowing a write command to bring the device out
of Shutdown mode. There will be no analog output at
the V
OUT
pin, and the V
OUT
pin is internally switched to
a known resistive load (500 k typical. Figure 4-4
shows the analog output stage during Shutdown mode.
The device will remain in Shutdown mode until it
receives a write command with <SHDN
> bit = 1 and the
bit is latched into the device. When the device is
changed from Shutdown to Active mode, the output
settling time takes less than 10 µs, but more than the
standard active mode settling time (4.5 µs).
FIGURE 4-4: Output Stage for Shutdown
Mode.
500 k 
Power-Down
Control Circuit
Resistive
Load
V
OUT
OP
Amp
Resistive String DAC