133 - MHz的时钟合成器/驱动器,用于PC主板用3态输出 133-MHz CLOCK SYNTHESIZER/DRIVER FOR PC MOTHERBOARDS WITH 3-STATE OUTPUTS
The CDC925 is a clock synthesizer/driver that generates system clocks necessary to support Intel Pentium III systems on CPU, CPU_DIV2, 3V66, PCI, APIC, 48MHz, and REF clock signals.
All output frequencies are generated from a 14.318-MHz crystal input. A reference clock input instead of a crystal can be provided at the XIN input. Two phase-locked loops PLLs are used, one to generate the host frequencies and the other to generate the 48-MHz clock frequency. On-chip loop filters and internal feedback loops eliminate the need for external components.
The host and PCI clock outputs provide low-skew and low-jitter clock signals for reliable clock operation. All outputs have 3-state capability, which can be selected via control inputs SEL0, SEL1, and SEL133/100\\\\.
The outputs are either 3.3-V or 2.5-V single-ended CMOS buffers. With a logic high-level on the PWR_DWN\ terminal, the device operates normally, but when a logical low-level input is applied, the device powers down completely, with the outputs in a low-level output state. When a high-level is applied to the PCI_STOP\ or CPU_STOP\, the outputs operate normally. With a low-level applied to the PCI_STOP\ or CPU_STOP\ terminals, the PCI or CPU and 3V66 outputs, respectively, are held in a low-level state.
The CPU bus can operate at 100 MHz or 133 MHz. Output frequency selection is done with corresponding setting for SEL133/100\ control input. The PCI bus frequency is fixed to 33MHz.
Since the CDC925 is based on PLL circuitry, it requires a stabilization time to achieve phase lock of the PLL. This stabilization time is required after power up or after changes to the SEL inputs are made. With use of an external reference clock, this signal must be fixed-frequency and fixed-phase before the stabilization time starts. View datasheet View product folder
频率 133 MHz
电源电压DC 3.13V min
输出接口数 24
供电电流 35 mA
电路数 1
耗散功率 1.5586 W
占空比 55% Max
工作温度Max 85 ℃
工作温度Min 0 ℃
耗散功率Max 1558.6 mW
电源电压 2.375V ~ 3.465V
电源电压Max 3.465 V
电源电压Min 2.375 V
安装方式 Surface Mount
引脚数 56
封装 SSOP-56
封装 SSOP-56
工作温度 0℃ ~ 85℃
产品生命周期 Active
包装方式 Tube
RoHS标准 RoHS Compliant
含铅标准 Lead Free