MCP4021T-502E/SN Microchip Technology, MCP4021T-502E/SN Datasheet - Page 41

• Manufacturer Part Number: MCP4021T-502E/SN
• Description: IC DGTL POT 5K 1CH 8SOIC
• Manufacturer: Microchip Technology

Specifications of MCP4021T-502E/SN

• Memory Type: Non-Volatile
• Taps: 64
• Resistance (ohms): 5K
• Number Of Circuits: 1
• Temperature Coefficient: 150 ppm/°C Typical
• Interface: Up/Down
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Resistance In Ohms: 5K
• End To End Resistance: 5kohm
• Resistance Tolerance: ± 20%
• No. Of Steps: 64
• Supply Voltage Range: 2.7V To 5.5V
• Control Interface: 2 Wire, Serial
• No. Of Pots: Single
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MCP4XXXDM-DB - BOARD DAUGHTER DIGIPOT MCP4XXXMCP402XEV - BOARD EVAL FOR MCP402X
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

6.1
6.1.1
When used as a rheostat, two of the three digital poten-
tiometer’s terminals are used as a resistive element in
the circuit. With terminal W (wiper) and either terminal
A or terminal B, a variable resistor is created. The resis-
tance will depend on the tap setting of the wiper and the
wiper’s resistance. The resistance is controlled by
changing the wiper setting.
The unused terminal (B or A) should be left floating.
Figure 6-2 shows the two possible resistors that can be
used. Reversing the polarity of the A and B terminals
will not affect operation.
FIGURE 6-2:
This allows the control of the total resistance between
the two nodes. The total resistance depends on the
“starting” terminal to the wiper terminal. At the code
00h, the R
resistance in maximized (R
code 3Fh, the R
R
The resistance step size (R
resistor.
The change in wiper-to-end terminal resistance over
temperature is shown in Figure 2-6, Figure 2-17,
Figure 2-27 and Figure 2-37. The most variation over
temperature will occur in the first few codes due to the
wiper resistance coefficient affecting the total resis-
tance. The remaining codes are dominated by the total
resistance tempco R
© 2005 Microchip Technology Inc.
BW
Note:
A
resistance in maximized (R
B
Resistor Configurations
BW
RHEOSTAT CONFIGURATION
To avoid damage to the internal wiper
circuitry in this configuration, care should
be taken to insure the current flow never
exceeds 2.5 mA.
resistance is minimal (R
AW
W
resistance is minimal (R
AB
Rheostat Configuration.
,
AB
S
) equates to one LSb of the
+ R
AB
W
). Conversely, at the
R
+ R
Resistor
AW
W
W
), but the R
).
or
W
), but the
R
BW
AW
6.1.2
When used as a potentiometer, all three terminals are
tied to different nodes in the circuit. This allows the
potentiometer to output a voltage proportional to the
input voltage. This configuration is sometimes called
voltage divider mode. The potentiometer is used to pro-
vide a variable voltage by adjusting the wiper position
between the two endpoints as shown in Figure 6-3.
Reversing the polarity of the A and B terminals will not
affect operation.
FIGURE 6-3:
The temperature coefficient of the R
minimal by design. In this configuration, the resistors all
change uniformally, so minimal variation should be
seen.
The wiper resistor temperature coefficient is different
from the R
node V
resistance, just the ratio of the R
temperature coefficient in most cases can be
ignored.
Note:
3
(Figure 6-3) is not dependent on this wiper
AB
POTENTIOMETER
CONFIGURATION
To avoid damage to the internal wiper
circuitry in this configuration, care should
be taken to insure the current flow never
exceeds 2.5 mA.
temperature coefficient. The voltage at
MCP4021/2/3/4
A
B
Potentiometer Configuration.
V
V
1
2
W
AB
DS21945C-page 41
resistors, so this
V
AB
3
resistors is