ICS2495

Integrated Circuit Systems, Inc. ICS2495 Dual Video/Memory Clock Generator Features Low cost - eliminates need for multiple crystal clock oscillators in video display subsystems Mask-programmable frequencies Pre-programmed versions for Industry Standard VGA chips Glitch-free frequency transitions Internal clock remains locked when the external frequency input is selected Low power CMOS device technology Small footprint - 16-pin DIP or SOIC Buffered Xtal Out Integral Loop Filter components Fast acquisition of selected frequencies, strobed or nonstrobed Guaranteed performance up to 135 MHz Excellent power supply rejection Advanced PLL for low phase-jitter Frequency change detection circuitry enhances new frequency acquisition and eliminates problems caused by programs that rewrite frequency information Description The ICS2495 Clock Generator is an integrated circuit dual phase-locked loop frequency synthesizer capable of generating 16 video frequencies and 4 memory clock frequencies for use with high performance video display systems. Utilizing CMOS technology to implement all linear, digital and memory functions, the ICS2495 provides a low-power, small-footprint, low-cost solution to the generation of video dot clocks. Outputs are compatible with XGA, VGA, EGA, MCGA, CGA, MDA, as well as the higher frequencies needed for advanced applications in desktop publishing and workstation graphics. Provision is made via a single level custom mask to imple...