Datasheet

MCP4011/2/3/4
DS21978C-page 38 © 2006 Microchip Technology Inc.
5.3 CS High Voltage
The CS pin is High-Voltage (V
IHH
) tolerant, like the
MCP402X. This allows the MCP401X to be used in
MCP402X applications without needing to change
other portions of the application circuit.
6.0 RESISTOR
Digital potentiometer applications can be divided into
two categories:
• Rheostat configuration
• Potentiometer (or voltage divider) configuration
Figure 6-1 shows a block diagram for the MCP401X
resistors.
FIGURE 6-1: Resistor Block Diagram.
Step resistance (R
S
) is the resistance from one tap
setting to the next. This value will be dependent on the
R
AB
value that has been selected. Table 6-1 shows the
typical step resistances for each device.
The total resistance of the device has minimal variation
due to operating voltage (see Figure 2-11, Figure 2-24,
Figure 2-36 or Figure 2-48).
TABLE 6-1: TYPICAL STEP RESISTANCES
Terminal A and B, as well as the wiper W, do not have
a polarity. These terminals can support both positive
and negative current.
R
S
A
R
S
R
S
R
S
B
N = 63
N = 62
N = 61
N = 1
N = 0
R
W
(1)
W
01h
Analog
Mux
R
W
(1)
00h
R
W
(1)
3Dh
R
W
(1)
3Eh
R
W
(1)
3Fh
Note 1: The wiper resistance is tap dependent.
That is, each tap selection resistance
has a small variation. This variation
effects the smaller resistance devices
(2.1 kΩ) more.
Part Number
Typical Resistance (Ω)
Total (R
AB
) Step (R
S
)
MCP401X-203E 2100 33.33
MCP401X-503E 5000 79.37
MCP401X-104E 10000 158.73
MCP401X-504E 50000 793.65