Application note

STM32G4 ADC use tips and recommendations

Rev 2 - October 2019

Introduction

The STM32G4 Series microcontrollers are designed to support high-end analog applications. These MCUs embed high-performance analog peripherals (ADCs, DACs, COMPs, OPAMPs, reference voltage) and high-performance digital components such as their Arm® Cortex®-M4 CPU, mathematical accelerators, DMA, and high-resolution timer among others.

This application note presents specific properties of the embedded ADCs in the STM32G4 Series and an introduction on how to properly design an application using those specific ADC properties.

This document introduces the specific ADC properties that influence the ADC accuracy of a final application and explains how to correctly design application hardware and software to improve the ADC accuracy for various application cases.

STM32G4 ADC features

This document uses as reference the specific STM32G4 ADC features listed in Table 1 ADC features on STM32G4 Series. This table presents the basic numeric values used as reference in the following sections.

Table 1. ADC features on STM32G4 Series
FeaturesValues for STM32G4 Series
Number of ADCsUp to 5
Resolution12 bits (or 10, 8, 6 bits), 16 bits with oversampling
Number of input channelsUp to 42
ADC principleSuccessive approximation register (SAR)
ADC clock frequencyUp to 60 MHz (up to 52 MHz in multiple-ADC operation case)
Sampling rateUp to 4 Msps (up to 3.46 Msps in multiple-ADC operation case)
Sampling time2.5 to 640.5 [ADC clock periods]
Supply voltageVDDA = 1.62 V to 3.6 V
Reference voltageOn dedicated VREF+ pin1 (internal or external), VREF+ = 1.62 V to VDDA (see datasheet)
TriggersFrom external pins or internal peripherals (timers)
Conversion modesSingle, continuous, scan-selected channels, discontinuous mode
OthersOffset calibration, analog watchdog, hardware oversampling, offset compensation, gain compensation, interleaved mode (two ADCs coupled), sampling time controlled by trigger edges, bulb mode sampling

For more detailed information on ADC features and characteristics on STM32G4 Series, refer to the corresponding products datasheet and reference manual (RM0440) available at www.st.com.

The STM32G4 Series microcontrollers are based on the Arm® Cortex®-M4 processor.
Note: Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.


1 In the LQFP128-pin packages, two VREF+ pins are available.