CY2280
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CY2280PVXC-11S (pdf) |
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CY2280PVXC-11ST |
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CY2280 100-MHz II Clock Synthesizer/Driver with Spread Spectrum for Mobile or Desktop PCs • Mixed 2.5V and 3.3V operation • Clock solution for II, and other similar pro- cessor-based motherboards Four 2.5V CPU clocks up to 100 MHz Eight 3.3V sync. PCI clocks, one free-running Two 3.3V 48-MHz USB clocks Three 3.3V Ref. clocks at MHz Two 2.5V APIC clocks at MHz or PCI/2 • EMI control Spread spectrum clocking Factory-EPROM programmable spread spectrum margin Factory-EPROM programmable output drive and slew rate • Factory-EPROM programmable CPU clock frequencies for custom configurations • Available in space-saving 48-pin SSOP package Functional Description The CY2280 is a Spread Spectrum clock synthesizer/driver for a Pentium II, or other similar processor-based PC requiring 100-MHz support. All of the required system clocks are provided in a space-saving 48-pin SSOP package. The CY2280 can be used with the CY231x for a total solution for systems with SDRAM. The CY2280 provides the option of spread spectrum clocking on the CPU and PCI clocks for reduced EMI. A downspread percentage is introduced when the SEL_SS input is asserted. The device can be run without spread spectrum when the SEL_SS input is deasserted. The percentage of spreading is EPROM-programmable to optimize EMI-reduction. The CY2280 has power-down, CPU stop, and PCI stop pins for power management control. The signals are synchronized on-chip, and ensure glitch-free transitions on the outputs. When the CPU_STOP input is asserted, the CPU clock outputs are driven LOW. When the PCI_STOP input is asserted, the PCI clock outputs except the free-running PCI clock are driven LOW. When the PWR_DWN pin is asserted, the reference oscillator and PLLs are shut down, and all outputs are driven LOW. CY2280 Selector Guide Clock Outputs CPU 100 MHz PCI CPU/2, CPU/3 USB 48 MHz APIC MHz APIC PCI/2 Reference MHz CPU-PCI delay CPU-APIC delay Spread Spectrum Downspread 4 8 2 3 ns N/A CY2280 Configuration Options 4 8 2 3 4 8 2 3 Logic Block Diagram CPU_STOP XTALIN XTALOUT PWR_DWN SEL0 SEL1 SEL100 SEL_SS PCI_STOP MHz OSC. CPU PLL Divider EPROM Delay SYS PLL -1 -2 STOP LOGIC STOP LOGIC Pentium is a registered trademark of Intel Corporation. APIC [0:1] VDDAPIC REF [0-2] VDDREF CPUCLK [0-3] VDDCPU PCICLK_F VDDPCI PCI [1-7] VDDPCI USBCLK [0:1] VDDUSB Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600 [+] Feedback CY2280 Pin Configurations REF0 1 REF1 2 XTALIN 4 XTALOUT 5 PCICLK_F 7 Ordering Information Ordering Code CY2280PVC-1 CY2280PVC-11S CY2280PVC-21S Package Name O48 Package Type 48-Pin SSOP 48-Pin SSOP 48-Pin SSOP Operating Range Commercial Page 10 of 12 [+] Feedback Package Diagram 48-Lead Shrunk Small Outline Package O48 CY2280 51-85061-B Page 11 of 12 Cypress Semiconductor Corporation, The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges. [+] Feedback CY2280 Document Title CY2280 100-MHz II Clock Synthesizer/Driver with Spread Spectrum for Mobile or Desktop PCs Document Number 38-07207 Issue Date Orig. of Change Description of Change 111721 12/16/01 DSG Change from Spec number 38-00694 to 38-07207 121842 12/14/02 Power up requirements added to Operating Conditions Information Page 12 of 12 [+] Feedback |
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