Analog-to-digital converter (ADC)

Overview
3×12-bit, 1.0 MSPS A/D converters are embedded and each ADC has up to 17 multiplexed channels allowing it measure signals from sixteen external and one internal sources,and 3 MSPS in triple interleaved mode
A/D conversion of the various channels can be performed in single, continuous, scan or discontinuous mode.
The analog watchdog feature allows the application to detect if the input voltage goes outside the user-defined high or low thresholds.
The ADC input clock is generated from the inter-connection logic clock.
Characteristics
(1) ADC sampling rate: 1 MSPS for 12-bit resolution
(2) Programmable sampling time
(3) 16 external analog inputs and 1 channel for internal temperature sensor or for VBAT
(4) Converts a single channel or scans a sequence of channels
(5) Single mode converts selected inputs once per trigger
(6) Continuous mode converts selected inputs continuously
(7) Discontinuous mode
(8) Analog watchdog
(9) ADC supply requirements: 3.0V to 3.6V, and typical power supply voltage is 3.3V
(10) ADC input range: VSSA ≤VIN ≤VREFP

Pins and internal signals
ADC internal signals

ADC pins definition

Temperature sensor
The temperature sensor can be used to measure the ambient temperature of the device. The sensor output voltage can be converted into a digital value by ADC. The sampling time for the temperature sensor is recommended to be set to at least 10μs.
The output voltage of the temperature sensor changes linearly with temperature. Because there is an offset, varies from chip to chip due to process variation, the internal temperature sensor is more suited for applications that detect temperature variations instead of absolute temperature.

ADC block pins



ADC input signals vs package pins


ADC characteristics

ADC timing diagram

After the start of ADC conversion and after 13 clock cycles, the EOC flag is set and the 12-bit Data is ready.