Datasheet
2008-2013 Microchip Technology Inc. DS22107B-page 45
MCP454X/456X/464X/466X
5.4 Shutdown
Shutdown is used to minimize the device’s current
consumption. The MCP4XXX achieves this through the
Terminal Control Register (TCON).
5.4.1 TERMINAL CONTROL REGISTER
(TCON)
The Terminal Control (TCON) register is a volatile
register used to configure the connection of each
resistor network terminal pin (A, B, and W) to the
Resistor Network. This bits are described in
Register 4-2.
When the RxHW bit is a “0”, the selected resistor net-
work is forced into the following state:
• The PxA terminal is disconnected
• The PxW terminal is simultaneously connected to
the PxB terminal (see Figure 5-2)
• The Serial Interface is NOT disabled, and all
Serial Interface activity is executed
• Any EEPROM write cycles are completed
Alternate low power configurations may be achieved
with the RxA, RxW, and RxB bits.
FIGURE 5-2: Resistor Network Shutdown
Configuration.
5.4.2 INTERACTION OF RxHW BIT AND
RxA, RxW, AND RxB BITS (TCON
REGISTER)
Using the TCON bits allows each resistor network (Pot
0 and Pot 1) to be individually “shutdown”.
The state of the RxHW bit does NOT corrupt the other
bit values in the TCON register nor the value of the
Volatile Wiper Registers. When the Shutdown mode is
exited (RxHW changes state from “0” to “1”):
• The device returns to the Wiper setting specified
by the Volatile Wiper value
• The RxA, RxB, and RxW bits return to controlling
the terminal connection state of that resistor net-
work
Note 1: The RxHW bits are identical to the RxHW
bits of the MCP41XX/42XX devices. The
MCP42XX devices also have a SHDN
pin which forces the resistor network into
the same state as that resistor networks
RxHW bit.
2: When RxHW = “0”, the state of the TCON
register RxA, RxW, and RxB bits is over-
ridden (ignored). When the state of the
RxHW bit returns to “1”, the TCON
register RxA, RxW, and RxB bits return to
controlling the terminal connection state.
In other words, the RxHW bit does not
corrupt the state of the RxA, RxW, and
RxB bits.
A
B
W
Resistor Network