This document shows the use of Pericom’s 32.768kHz XO to Drive 2-IC in Sports Camera Design. 32.768kHz frequency is the basis of timing for counting seconds, minutes, and hours in most clocks. The frequency is also commonly used in the watch dog mechanism of microprocessors as a standby clock. In other words, the presence of a 32.768kHz clock is required in almost all applications. There are two ways to generate this 32.768kHz clock. The first one is to use a 32.768kHz tuning fork crystal (Xtal) connected to an ASIC or core chip. And the other is to use a 32.768kHz Crystal Oscillator (XO), which provides more advantages than a crystal.
However not all 32.768kHz crystal oscillators are made the same. If a crystal oscillator is made from a tuning fork crystal, then the overall performance will be similar to the crystal such as stability and start up time. Pericom uses a different approach to make a 32.768kHz XO. By applying its unique XO IC design capability, Pericom is able to use MHz crystal blanks to produce 32.768kHz oscillators with very tight stability while achieving very low current compared to what tuning forks can do.