The MK1432 and MK1434 are low cost, high performance triple clock synthesizers for green PC and local bus desktop and notebook applications. Using analog Phase-Locked Loop (PLL) techniques, the devices accept a 14.318 MHz crystal input to produce multiple output clocks up to 100 MHz. They provide selectable 2XCPU and CPU, selectable local bus clock, ISA clock, and one fixed peripheral clock. The chips support PCI and VL buses. The fixed clock is either 24MHz or 40MHz. The devices can operate at 5V or 3.3V up to and including 80MHz on the 2XCPU clock. The Power Saving pin causes the CPU clocks to smoothly transition to 33.33 MHz for Pentiums, and 16.67 MHz for 486DX4. In addition, a single pin can be made to slow DX2s to 8 MHz.
The MK1432 and MK1434 are triple clock synthesizers designed for green PC and local‑bus desktop and notebook applications. They accept a 14.318 MHz crystal and generate multiple output clocks up to 100 MHz, including selectable 2XCPU, CPU, local‑bus, ISA and a fixed peripheral clock. The devices operate from 3 V to 5 V and include a Power Saving pin that can lower CPU clock frequencies for low‑power operation.
The parts are supplied in a 16‑pin narrow SOIC package and feature low skew (<250 ps) and a 45/55 % duty cycle up to 100 MHz. Electrical specifications include a 3.0‑5.5 V operating supply range, 2 V input high threshold, 0.8 V input low threshold, and 25 mA TTL‑level output drive capability. Fixed output clocks are 24 MHz for the MK1432 and 40 MHz for the MK1434.
| Operating Supply Voltage (VDD) | 3.0 V – 5.5 V |
|---|---|
| Input High Voltage (VIH) | 2 V |
| Output High Voltage (VOH) at 25 mA | 2.4 V |
| Output Drive Capability | 25 mA at TTL levels |
| Package Type | 16‑pin narrow SOIC |
| Fixed Clock Output (MK1432) | 24 MHz |
| Fixed Clock Output (MK1434) | 40 MHz |
Both devices require a 14.318 MHz crystal.
The devices are rated for an ambient operating temperature up to 70 °C.