MCP4532 MICROCHIP [Microchip Technology], MCP4532 Datasheet - Page 42

• Manufacturer Part Number: MCP4532
• Description: 7/8-Bit Single/Dual I2C Digital POT with Volatile Memory
• Manufacturer: MICROCHIP [Microchip Technology]

MCP453X/455X/463X/465X
5.2
Each tap point (between the R
connection point for an analog switch. The opposite
side of the analog switch is connected to a common
signal which is connected to the Terminal W (Wiper)
pin.
A value in the volatile wiper register selects which
analog switch to close, connecting the W terminal to
the selected node of the resistor ladder.
The wiper can connect directly to Terminal B or to
Terminal A. A zero-scale connections, connects the
Terminal W (wiper) to Terminal B (wiper setting of
000h). A full-scale connections, connects the Terminal
W (wiper) to Terminal A (wiper setting of 100h or 80h).
In these configurations the only resistance between the
Terminal W and the other Terminal (A or B) is that of the
analog switches.
A wiper setting value greater than full-scale (wiper
setting of 100h for 8-bit device or 80h for 7-bit devices)
will also be a Full-Scale setting (Terminal W (wiper)
connected to Terminal A).
wiper setting map.
Equation 5-2
mine the resistance between the wiper and terminal B.
EQUATION 5-2:
DS22096A-page 42
N = 0 to 256 (decimal)
N = 0 to 128 (decimal)
R
R
Wiper
WB
WB
=
=
illustrates the calculation used to deter-
R
------------- -
(
R
------------- -
(
256
128
AB
AB
N
N
)
)
+
+
R
WB
R
R
W
W
Table 5-1
CALCULATION
8-bit Device
7-bit Device
S
illustrates the full
resistors) is a
TABLE 5-1:
7-bit Pot 8-bit Pot
3FFh
081h
080h
07Fh
041h
040h
03Fh
001h
000h
Wiper Setting
3FFh
0FFh
101h
100h
080h
07Fh
000h
081
001
VOLATILE WIPER VALUE VS.
WIPER POSITION MAP
Reserved (Full-Scale (W = A)),
Increment and Decrement
commands ignored
Full-Scale (W = A),
Increment commands ignored
W = N
W = N (Mid-Scale)
W = N
Zero Scale (W = B)
Decrement command ignored
© 2008 Microchip Technology Inc.
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