The SiT3521 is an ultra-low jitter, user programmable oscillator which offers the system designer great flexibility and functionality. The device supports two in-system programming options after powering up at a default, factory programmed startup frequency:
- Any-frequency mode where the clock output can be re-programmed to any frequency between 1 MHz and 340 MHz in 1 Hz steps
- Digitally controlled oscillator (DCO) mode where the clock output can be steered or pulled by up to ±3200 ppm with 5 to 94 ppt (parts per trillion) resolution.
The device’s default start-up frequency is specified in the ordering code. User programming of the device is achieved via I2C or SPI. Up to 16 I2C addresses can be specified by the user either as a factory programmable option or via hardware pins, enabling the device to share the I2C with other I2C devices.