Thing Plus USB-C Power Regulation

Development Boards ESP32
1

I’m confused about the MOSFET that controls the power source on the Thing Plus USB-C: [schematic

The hook up guide explains “As a depletion type P-channel MOSFET, the mosfet acts as a normally closed switch when the gate threshold voltage is zero.” but:

  1. the schematic shows a normal enhancement MOSFET

  2. no one seems to even manufacture a depletion p-channel MOSFET

  3. the MOSFET looks like it is hooked up backwards with V_d > V_s when powering with only a battery

Does the MOSFET actually turn on/off, or is the current really just going through MOSFET’s body diode when running on battery power? (more like the power select circuit on the [LoRa Thing Plus](https://cdn.sparkfun.com/assets/4/4/f/7/e/expLoRaBLE_Thing_Plus_schematic.pdf?_gl=1*1g92jhf*_ga*MjA1ODA0MDgyMC4xNjU4MzU1MjM4*_ga_T369JS7J9N*MTY5ODA5ODQzOC4zOC4xLjE2OTgxMDU1NTguMjkuMC4w)](https://cdn.sparkfun.com/assets/learn_tutorials/2/3/5/3/power_control_circuits.png?_gl=1*70fwu7*_ga*MjA1ODA0MDgyMC4xNjU4MzU1MjM4*_ga_T369JS7J9N*MTY5ODA5ODQzOC4zOC4xLjE2OTgxMDIzOTIuMTQuMC4w)

2

I’ll send a ping and ask engineering :slight_smile: