The CDC9843 is a high-performance clock synthesizer/driver that generates the system clocks necessary to support Pentium®/82430HX/82430VX and PentiumPro 82440FX chipsets. Four host-clock outputs (HCLKn) are programmable to one of three frequencies (50 MHz, 60 MHz, or 66 MHz) via the SEL0 and SEL1 control inputs. Six PCI-clock outputs (PCLKn) are half the frequency of CPU clock outputs and are delayed 1 ns to 4 ns from the rising edge of the CPU clock. In addition, a universal serial bus (USB) clock output at 48 MHz (SBCLK), a floppy controller clock at 24 MHz (FCCLK), and two 14.318-MHz reference clock outputs (REF0, REF1) are provided. All output frequencies are generated from a 14.318-MHz crystal input.
The CDC9843 is a high-performance clock synthesizer/driver designed to generate system clocks necessary to support Pentium™/82430HX/82430VX and Pentium Pro 82440FX chipsets. It provides four programmable host-clock outputs, six PCI clock outputs, one 48-MHz USB clock output, one 24-MHz floppy controller output, and two reference clock outputs.
All output frequencies are derived from a single 14.318-MHz crystal input or an external reference clock. The device utilizes internal loop filters for its phase-locked loops (PLLs), eliminating the need for external components. It operates at a supply voltage of 3.3 V and is packaged in a plastic small-outline package.
| Supply Voltage (Voc) | 3.135 V to 3.6 V |
|---|---|
| Operating Temperature Range | 0°C to 70°C |
| Host Clock Frequencies | 50 MHz, 60 MHz, or 66 MHz |
| USB Clock Frequency | 48 MHz |
| Floppy Controller Output Frequency | 24 MHz |
| Reference Clock Frequency | 14.318 MHz |
It supports Pentium™/82430HX/82430VX and Pentium Pro 82440FX chipsets.
No, it has internal loop filters that eliminate the need for external components.
The stabilization time required after power up is 5 ms.