MK1491E-14RTR

MK1491E-14RTR Features

The MK1491-14 is a low cost, low jitter, highperformance clock synthesizer for OPTi’sFirestar and Firestar+ chipsets for Pentium™Processor-based mobile computer applications.Using analog Phase-Locked Loop (PLL)techniques, the device uses a 14.318 MHzcrystal input to produce multiple outputclocks up to 75 MHz. It provides selectableHost and PCI local bus clocks as well asselectable clocks for Super I/O or UniversalSerial Bus (USB). The device has up to sevenHost output clocks.The chip has three different power downmodes that reduce power on various clocks. • Packaged in 28 pin, 150 mil wide SSOP • Provides all critical timing for OPTi ACPI Firestarand Firestar+ • Early Host clock of 3.5ns • Separate VDD and skew adjust for Host 5,6, and 7supports field upgrade to Firestar+ and new 2.5Vprocessors • 48MHz USB, 24MHz SIO, and Audio clock support • Single pin CPU(Host) slowdown to 33.3MHz • Multiple power down modes • Low EMI Enable pin reduces EMI radiation (patentpending)CrystalOscillatorVDDGNDHOST/PCIClocksSTOP#SEL014.31818 MHzcrystalOutputBuffersOutputBufferFixedClockOutputBuffersXIXOPSVDDHOST1-4SEL1Host/2F2HOST 5, 7PCI 1:5SLOW#Low EMI EnableOutputBuffer14.318 MHzF1OutputBufferFS1:0Synch./Asynch. PCIHOST1:4OutputBuffers425VDDHOST5-7EHOST633MMUXHS34

MK1491E-14RTR Description

MK1491E-14RTR Processor-based mobile computer applications.

MK1491E-14RTR Pin Descriptions

Table #2. Host/PCI Frequency Select (MHz)