ICS9169C-231 Datasheet | Integrated Circuit Systems

.. Integrated Circuit Systems, Inc. Frequency Generator for Pentium™ Based Systems General Description The ICS9169C-231 is a low-cost frequency generator designed specifically for Pentium and Pentium-Pro based chip set systems. The integrated buffer minimizes skew and provides all the clocks required. A 14.318 MHz XTAL oscillator provides the reference clock to generate standard Pentium frequencies. The CPU clock makes gradual frequency transitions without violating the PLL timing of internal microprocessor clock multipliers. A raised frequency setting of 68.5 MHz is available for Turbo-mode of the 66.8 MHz CPU. The ICS9169C-231 contains 8 CPU clocks, 6 PCI clocks, 1 REF at 48MHz and 1 at 24MHz. Either synchronous (CPU/2) or asynchronous (32 MHz) PCI bus operation can be selected by latching data on BSEL input. Features - - - - - - - - - - - Eight selectable CPU clocks operate up to 83.3 MHz Frequency selections include Turbo-mode speed of 68.5 MHz Maximum CPU jitter of ±200ps Six BUS clocks support sync or async bus operation 250ps skew window for CPU outputs, 500ps skew window for BUS outputs CPU clocks to BUS clocks skew 1-4 ns (CPU early) 48 MHz clock for USB support & 24 MHz clock for FD. Logic inputs latched at Power-On for frequency selection saving pins as Input/Output Integrated buffer outputs drive up to 30p F loads 3.0V - 3.7V supply range, CPU (1:8) outputs 2.5V (2.375 - 2.6V) VDD option 28-pin SOIC or SSOP package Block Diagram Pin Configuration . Data Shee 28-Pin SOIC or SSOP Functionality 3.3V±10%, 0-70°C Crystal (X1, X2) = 14.31818 MHz ADD RESS SEL ECT CP U(1:8) (MHz) BU S (1:6)MHz 48MHz 24MHz RE F FS2 FS1 FS0 0 1 0 1 0 1 0 1 50 60 66.8 75.9 55 75.9 83.3 68.5 BSEL=1 BSEL=0 25 30 33.4 32 27.5 37.5 41.7 34.25 32 32 32 32 32 32 32 32 48 48 48 48 48 48 48 48 24 24 24 24 24 24 24 24 REF REF REF REF REF REF REF REF VDD Groups: VDD1 = X1, X2, REF/BSEL VDD2 = CPU1-6 VDD3 = CPU7-8 & PLL Core VDD4 =...