The IDT9173B provide the analog PLL circuit blocks to implement a frequency multiplier. Because the device is configured to use an external divider in the PLL clock feedback path, a large divider can be used to result in a large frequency multiplication ratio. This is useful when using a low frequency input clock to generate a high frequency output clock. The IDT9173B contains a phase detector, charge pump, loop filter, and voltage-controlled oscillator (VCO). The IDT674-01 can be used as the external feedback divider.