Introduction

This application note describes a low-power solution to measure the V_CC/Battery voltage without using any I/O pins or external components.

The core idea is to let the internal reference voltage V_bg act as ADC input, and the target V_CC act as ADC reference.

This solution helps the users setting up applications with low power consumption, low MCU pin count, and/or few BOM parts.

For better resolution, this solution should be optimized due to its non-linearity. In general voltage/battery monitoring, the solution is quite attractive.