4.14 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 3V regulator. When the battery voltage is near to the required minimum input voltage of the regulator, it may 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 WBZ451 Curiosity Board is designed by default for evaluating the WBZ451PE module and associated peripherals with an on-board 3V regulator. The following limitations apply for the circuitry if the WBZ451PE module and associated circuitry is powered from external power supply header at other voltages:
  • QSPI Serial Flash SST26VF064B (U6) – Standard operating voltage for the QSPI serial Flash is 2.3V – 3.6V operation
  • Temperature Sensor MPC9700A (U3) – Standard operating voltage for the temperature sensor is 2.3V – 3.6V operation
  • User LED (D5) – Designed for 3V operation; LED brightness at lower voltages will be dull or no glow. To increase the emitted light level, the value of the series resistor (R42) can be lowered.
  • RGB Lighting LED (D6) – RGB lightning LED is powered from VBAT net. It requires either USB or battery power supply to be plugged in to be functional.