MCP402XEV Microchip Technology, MCP402XEV Datasheet - Page 12

• Manufacturer Part Number: MCP402XEV
• Description: BOARD EVAL FOR MCP402X
• Manufacturer: Microchip Technology

Specifications of MCP402XEV

• Main Purpose: Digital Potentiometer
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: MCP4021
• Primary Attributes: 1 Single Pot, 10 kOhm, 64 Tap, Non Volatile
• Secondary Attributes: 2.7 ~ 5.5 V, 150 ppm/°C
• Processor To Be Evaluated: MCP402X
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

MCP401X/2X Evaluation Board User’s Guide
DS51546B-page 8
2.2.1
The MCP4021/11-XXXI/SN is an 8-pin digital potentiometer device with terminals A, B
and W available on the device pins. Footprint U1 supports the 150 mil SOIC package.
Resistors R2 and R3 are 2.5 k on the populated PCB, along with the 10 k
MCP4021-103I/SN digital potentiometer. This creates a “windowed” voltage divider
with a transfer function illustrated in Equation 2-1.
EQUATION 2-1:
2.2.2
The MCP4022/12-XXXI/OT is a 6-pin, stand-alone digital rheostat with terminals A and
W available on the device pins. Footprint U2 supports the SOT-23-6 package. An
“INCR” command moves the wiper toward terminal A, thus causing the resistance
across the rheostat to decrease. A “DECR” command moves the wiper toward terminal
B, thus causing the resistance across the rheostat to increase.
Note 1:
Note 1:
2:
2:
3:
Evaluating the MCP4021 and MCP4011
Evaluating the MCP4022 and MCP4012
DO NOT populate U2 if using U1.
The MCP4011 has high-voltage tolerant pins and, therefore, accepts
high-voltage Increment and Decrement commands. Since this device is
nonvolatile, the WiperLock™ Technology feature is not present.
DO NOT populate U1 if using U2.
The included MCP4021 digital potentiometer samples could be used to
evaluate the MCP4022 simply by not populating R3 and letting terminal
B float.
The MCP4012 has high-voltage tolerant pins and, therefore, accepts
high-voltage Increment and Decrement commands. Since this device is
nonvolatile, the WiperLock™ Technology feature is not present.
V
wiper
WINDOWED POTENTIOMETER – VOLTAGE DIVIDER
CALCULATION
=
Where:
V
------------------------------------------ -
R2
DD
d = the wiper setting (0 to 63)
+
R3
R
wb
+
+
R
nom
R3
=
5.0V
---------------------------------------------------------------------
2.5k
d 10k
+
2.5k
© 2005 Microchip Technology Inc.
+
63
10k
+
2.5k