Description
The ICS1572 is a high performance monolithic phase-locked loop (PLL) frequency synthesizer. Utilizing ICS’s advanced CMOS mixed-mode technology, the ICS1572 provides a low cost solution for high-end video clock generation in worksta tions and high-end PC applications.
The ICS1572 has differential video clock outputs (CLK+ and CLK-) that are compatible with industry standard video DACs. Another clock output, LOAD, is provided whose frequency is derived from the main clock by a programmable divider. An additional clock output is available, LD/N2, which is derived from the LOAD frequency and whose modulus may also be programmed.
Operating frequencies are fully programmable with direct control provided for reference divider, pre-scaler, feedback divider and post-scaler.
Reset of the pipeline delay on Brooktree RAMDACs™ may be performed under register control. Outputs may also be set to desired states to facilitate circuit board testing.

Features
• Supports high-resolution graphics - CLK output to 180 MHz
• Eliminates need for multiple ECL output crystal oscillators
• Fully programmable synthesizer capability - not just a clock multiplier
• Available in 20-pin 300-mil wide body SOIC package
• Available in both parallel (101) and serial (301) programming versions
• Circuit included for reset of Brooktree RAMDAC pipeline delay

Applications
• Workstations
• AutoCad Accelerators
• High-end PC graphics systems