特長
- Packaged in 20-pin SSOP (QSOP) – Pb-free, RoHS compliant
- Highly accurate frequency generation
- M/N Multiplier PLL: M = 1..2048, N = 1..1024
- Serially programmable: user determines the output frequency via a 3-wire interface
- Spread Spectrum frequency modulation for reduced system EMI
説明
The 309 is a versatile serially-programmable, triple PLL with spread spectrum clock source. The 309 can generate any frequency from 250kHz to 200 MHz, and up to 6 different output frequencies simultaneously. The outputs can be reprogrammed on-the-fly, and will lock to a new frequency in 10 ms or less. To reduce system EMI emissions, spread spectrum is available that supports modulation frequencies of 31 kHz and 120 kHz, as well as modulation amplitudes of +/-0.25% to +/-2.0%. Both center and down-spread options are available. The device includes a PDTS pin which tri-states the output clocks and powers down the entire chip. The 309 default for non-programmed start-up are buffered reference clock outputs on all clock output pins. IDT's VersaClockTM programming software allows the user to configure up to 9 outputs with target frequencies, spread spectrum capabilities or buffered reference clock outputs. The VersaClockTM software automatically configures the PLLs for optimal overall performance.