Functional Description
The CY7B991 and CY7B992 Programmable Skew Clock Buffers (PSCB) offer user-selectable control over system clock functions. These multiple-output clock drivers provide the system integrator with functions necessary to optimize the timing of high-performance computer systems. Eight individual drivers, arranged as four pairs of user-controllable outputs, can each drive terminated transmission lines with impedances as low as 50Ω while delivering minimal and specified output skews and full-swing logic levels (CY7B991 TTL or CY7B992 CMOS).

FEATUREs
• All output pair skew <100 ps typical (250 max.)
• 3.75- to 80-MHz output operation
• User-selectable output functions
   — Selectable skew to 18 ns
   — Inverted and non-inverted
   — Operation at 1⁄2 and 1⁄4 input frequency
   — Operation at 2x and 4x input frequency (input as low as 3.75 MHz)
• Zero input to output delay
• 50% duty-cycle outputs
• Outputs drive 50Ω terminated lines
• Low operating current
• 32-pin PLCC/LCC package
• Jitter < 200 ps peak-to-peak (< 25 ps RMS)
• Compatible with a Pentium™-based processor