The 9LPRS477 is a main clock synthesizer chip that provides all clocks required for ATI RD7xx-based systems using AMD processors. An SMBus interface allows full control of the device.


  • Features/Benefits
    • CPU, ATIG, SB_SRC and SRC outputs are independently programmable for frequency
    • Spread Spectrum for EMI reduction 
    • Outputs may be disabled via SMBus
    • External crystal load capacitors for maximum frequency accuracy
    • Meets PCIEX Gen2 specifications
    • Meets 30kHz to 33kHz SRC modulation rate specification for USB3.0
  • Key Specifications 
    • CPU outputs cycle-to-cycle jitter < 85ps
    • SRC outputs cycle-to-cycle jitter < 125ps
    • ATIG outputs cycle-to-cycle jitter < 125ps
    • ± 300ppm frequency accuracy on CPU, SRC & ATIG clocks

Product Options

Part Number Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Active VFQFPN 64 C Yes Tray
Active VFQFPN 64 C Yes Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
9LPRS477D Datasheet Datasheet PDF 440 KB
9LPRS477C Datasheet Datasheet PDF 308 KB
PCN# : A1904-01 Add Greatek, Taiwan as an Alternate Assembly Facility Product Change Notice PDF 983 KB
PCN# : A1611-02 Add JCET China as Alternate Assembly and Change of Material Set at Alternate Assembly Location Product Change Notice PDF 583 KB
PCN# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB
PCN# : A1311-03R1 Alternate Assembly Locations Product Change Notice PDF 43 KB