Introduction

This application note demonstrates the effectiveness of the Analog Peripheral Manager (APM), an integrated peripheral of the PIC18-Q71 device family, in reducing power consumption by enabling and disabling the controlled analog peripherals.

A system or device intended to run with low-power consumption is known as a low-power application. These applications often aim to reduce total power needs, increase battery life and improve energy efficiency. Low-power applications for microcontrollers (MCUs) entail developing and prioritizing using energy-saving hardware and software solutions, which is a critical factor for portable electronics, battery-operated devices and other equipment in situations where power sources are limited or energy efficiency is of utmost importance.

Sleep mode is a low-power mode designed to conserve energy in electronic devices. When a device enters Sleep mode, it reduces power consumption by shutting down nonessential functions while maintaining the ability to quickly resume normal operation when needed. Thus, it can significantly extend the battery life of portable devices, reduce energy costs in larger systems and minimize the overall environmental impact of electronic devices. PIC18-Q71 features various Sleep modes to help designers optimize power consumption in their applications.

The APM allows analog modules to be core independently switched on and off periodically using timers. This feature can be used to manage analog peripherals available on the device, such as the Analog-to-Digital Converter (ADC), Comparator (CMP), Digital-to-Analog Converter (DAC) or Operational Amplifier (OPA) modules. This peripheral is ideal for low-power applications with analog sensors that only need to be periodically measured, as opposed to sensors that must be continuously monitored. With the APM, users can set custom time intervals in which configured analog modules will activate to perform a specified function periodically before deactivating and returning to a low-power state after the programmed time has elapsed. Furthermore, the APM facilitates optimizing the total power consumption in applications by activating analog peripherals without waking up the CPU.

The main idea of the project consists in benchmarking three similar applications, each of which utilize different low-power techniques as described below:

• Ambient Temperature Basic Application - Shows the highest power consumption case by not using any power-saving methods
• Ambient Temperature Application with APM - Shows improvements in power savings by using the APM in conjunction with the previous example
• Ambient Temperature Application with APM and Sleep mode - Shows the optimal low-power application through the use of the APM and Sleep mode technique