Hi, I'd like to use Beagleboard to control a 2-channel digital potentiometer (Microchip MCP42050: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010498) through SPI.
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 ground) resistors? 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 divider? 4. Should I worry about current ratings? Sorry for the newbie questions. Thanks in advance for the answers. -- []'s Rodrigo -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
