I have a thermostat that outputs a DC power supply for a communication daughter board. When I read it with the voltmeter, it reads ~3.9v, but the zigbee module that I want to use requires 3.3v regulated.
Since its a tight squeeze inside the thermostat, I have to stick with SMD components. I looked at the the MCP1703 in the SOT-223-3 to do the job, but in the example schematic, the input voltage is 9v so I'm hesitant to use the 1uF input and output filter caps that they used.
Do I need an oscilloscope in order to do this right? Can I just use the example caps even though my input voltage is ~3.9v rather than 9v? How "clean" does my output voltage need to be for a typical zigbee module?