I2779A

Production February 2003 ® P2779A Low-Cost Notebook EMI Reduction IC Features Provides up to 15 dB of EMI suppression FCC approved method of EMI attenuation Generates a 1X low EMI spread spectrum clock of the input frequency Operates between 20MHz and 38MHz input frequency range External loop filter for spread percentage adjustment Spreading ranges from ±0.25% to ±2.5% Ultra low cycle-to-cycle jitter Zero-cycle slip at small deviations 3.3 V operating voltage range 10 mA output drives TTL or CMOS compatible outputs Low power CMOS design Available in 8-pin SOIC and TSSOP Available for industrial temperature operating range (-40º C to 85º C) Block Diagram PD LF VDD XIN XOUT Modulation Crystal oscillator Frequency divider Feedback divider Phase detector Loop filter PLL VCO Output divider REF ModOUT VSS Product Description The P2779A is a versatile spread spectrum frequency modulator designed specifically for mobile and digital camera and other digital video and imaging applications. The P2779A reduces electromagnetic interference (EMI) at the clock source, which provides system-wide reduction of EMI of all clock dependent signals. The P2779A allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The P2779A uses the most efficient and optimized modulation profile approved by the FCC. The P2779A modulates the output of a single PLL in order...