Nordic Thingy:91™ uses a power management IC (PMIC) as internal power management. The PMIC includes a battery charger, a fuel gauge and two regulator outputs.
The PMIC has three voltage domain outputs that are used on Nordic Thingy:91:
- VSYS used for the nRF9160 System in Package (SiP)
- One 1.8 V output used as General-Purpose Input/Output (GPIO) voltage
- One 3.3 V output used for analog circuitry
The 1.8 V domain supplies the nRF52840, the accelerometers, the environment sensors, and the GPIOs of the nRF9160. This domain must always be on for Nordic Thingy:91 to work.
The 3.3 V domain supplies the LEDs, the color sensor, the buzzer, the RF switches and the Global Positioning System (GPS) Low-Noise Amplifier (LNA). This power domain can be powered down to save power when Nordic Thingy:91 is in sleep mode.
Figure 1. PMIC schematic
