HVDigitalPot2F

High Voltage Digital Pot (10-bit) Fast Version

File:Backhvpot2F.png

Features

Most digital potentiometers are limited in the voltages that they can have at the end terminals to be within +5V and Ground. This makes operation with high voltages difficult. This design allows for higher voltages on the end terminals.

• Supports SPI transfers (much faster than Arduino bit banging)
• Single-channel, 256-/1024-position resolution
• 20 kΩ, 50 kΩ, and 100 kΩ nominal resistance
• Maximum ±1% nominal resistor tolerance error (resistor performance mode)
• 20-times programmable wiper memory
• Rheostat mode temperature coefficient: 35 ppm/°C
• Voltage divider temperature coefficient: 5 ppm/°C
• +9 V to +33 V single-supply operation
• +9 V to -16.5 V dual-supply operation
• See data sheet for additional features

D/A Converter

ICs are Analog Devices part number AD5292 PDF Datasheet.

Connectors

J1 - 8 pin Header

1. +12V - High Voltage Power
2. GND - Ground
3. +5V - Digital Logic Power
4. Din - Data In
5. CLK - Clock In
6. CS1 - Chip Select for Pot 1
7. CS2 - Chip Select for Pot 2
8. GND - Ground

J2/J3 - 3 pin Header

1. A side
2. Wiper
3. B side

Driver

Here is the 10-bit High Voltage Arduino Driver. This driver needs to be modified to use the SPI interface.

Accelerating Writes

Here are some notes on accelerating writes by using the SPI bus pins on the Arduino. Note that this card is an improvments over the HVDigitalPot2 since it has separate chip select lines which allows SPI transfers to be done.