I'd like to use Beagleboard to control a 2-channel digital
potentiometer (Microchip MCP42050:
As the chip will only funcion with VDD above 2.7V, I'll power it using
the 5V power rail (pin 2). But its digital output reaches 4.5V
(high-level; 0.4V for low-level).
I have the following questions:
1. I'll have to protect Beagleboard SPI input (SOMI) against such a
"high" voltage, right?
2. To get it down to 1.8V is it enough to use a voltage divider
consisting of 10k (chip output to bb input) and 5k6 (bb input to
3. Is it better to get the voltage down to 2.7V (again using a voltage
divider, resistor values to be calculated) before getting to VDD pin,
and then from 2.2V (SOMI high-level output) to 1.8V using another
4. Should I worry about current ratings?
Sorry for the newbie questions. Thanks in advance for the answers.