P1817B - Alliance Semiconductor

P1817B Low-Power Mobile VGA EMI Reduction IC

The P1817 is a versatile spread spectrum frequency modulator designed specifically for input clock frequencies. The P1817 reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of SR0 SSON Block Diagram VDD Modulation XIN Crystal Oscillator XOUT Frequency Divider Feedback Divider Ref Phase Detector Loop Filte.

Features

FCC approved method of EMI attenuation. Generates a low EMI spread spectrum clock of the input frequency. Optimized for frequency range from: o o P1817A
  – 20 to 30MHz. Operation P1817B
  – 10 to 20MHz Operation P1817A/B down stream clock and data dependent signals. The P1817 allows significant system cost savings by reducing the number of circuit board layers ferrite beads, shielding and other passive components that are traditionally required to pass EMI regulations. The P1817 modulates the output of a single PLL in order to “spread” the bandwidth of a synthesized clock, and more importantly,.