Let Your Micro Sleep Without One Eye on the Clock

Abstract

Nowadays, the timekeeping real-time clock (RTC) circuit is commonly integrated into the system microcontroller of portable devices. However, on close inspection, it is becoming apparent that this approach prevents the micro from ever entering an ultra-low power deep-sleep mode. In this article, we show that by using a tiny external RTC IC, this problem can be overcome, allowing portable devices to save even more power when not in use.