Power supply

[leloup314]

An possible configuration which would allow us to enable bipolar in- and outputs is the following:

• Have a 5 VDC commercial power supply to power everything
• Use a nice LDO line regulator with charge pump to generate +-5V from the single 5 VDC

Such an IC is the TI LM27762 which can generate very stable +- 5V from single 5V input while supplying +-250 mA current (Looks like this is the maximum the Nano board should consume (see here). The other ICs on the PCB should not consume a lot so I think this yould be a nice solution to get bipolar +- 5V

[leloup314]

The TI LM27762 should be used to provide +- 1.65 V ( 3V3 / 2) for powering our transimpedance amps as well as our ADCs (AGND & AVDD, DGND & DVDD should be 0-3V3 from Arduino)

[leloup314]

The TI LM27762 as well as the Arduino (VIN pin, has LDO so no need to regulate) should be powered from the 5VDC power supply

[leloup314]

We should use a 5V LDO e.g. LDL1117S50R to produce the 5 V rail for the LM27762 and use a 9 VDC power supply. This we feed in the VIN of arduino since the 5V on VIN is quite low for the on-board LDO to properly work.