3.15 Limitations of Using Battery and External Power Supply

Battery Power:

The battery management circuit is designed for a 4.2V battery going to a downstream 3.3V regulator. When the battery voltage is near the required minimum input voltage of the regulator, it can affect the regulated output. It is advised to use a fully charged battery for evaluation, and recharge the battery as soon as the low battery output indicator is turned ON at 3.1V.

External Power Supply Header:

The WBZ351 Curiosity Board is designed by default for evaluating the WBZ351PE Module and associated peripherals with the on-board 3.3V regulator. The following limitations apply for the circuitry if the WBZ351PE Module and associated circuitry is powered from the external power supply header at other voltages:
  • QSPI Serial Flash (SST26VF064B-104I/MF) (U7) – Standard operating voltage for the QSPI serial Flash is 2.3-3.6V operation
  • Temperature Sensor (MPC9700A) (U3) – Standard operating voltage for the temperature sensor is 2.3-3.6V operation
  • User LED (D5) – Designed for 3.3V operation; LED brightness at lower voltages is dull or no glow. To increase the emitted light level, lower the value of the series resistor (R42).
  • RGB Lighting LED (D6) – VBAT net powers the RGB lightning LED. To be functional, plug in either the USB or battery power supply.