We are considering the MP3320B as driver for the RGB signal LED on an IoT sensor. We have two voltage rails:
- Vi2c=2.3V which powers all I²C devices on the sensor
- Vbat=3.3V which powers devices that need a higher operating voltage.
It must be possible to have Vbat=0V with Vi2c=2.3V as well as Vi2c=0V with Vbat=3.3V. In other words, we have to be able to set one of the voltage rails to zero without extra current leak.
Based on Figure 3 of the datasheet we want to operate it like this:
The questions we have are:
- Is this setup possible at all?
- Should we connect Vbat to OUT or rather not?
- Will it be possible to have either Vi2c or Vbat to be 0V? Or are internal (parasitic) diodes prohibiting this?
- Will a toggle on Vin (Vi2c in this case, which also takes the SDA/SCL down) indeed reset the internal I²C state machine of the MP3320B?
Thank you for any guidance, best regards, Ruud.