What the CY7B994V is and where it fits
The Cypress CY7B994V is a PLL-based clock driver from the RoboClock™ family, configured as a clock buffer and fanout distribution device. It accepts up to four input clocks (LVPECL or LVTTL) and drives eighteen LVTTL outputs, all from a single 2.97 V to 3.63 V supply. The integrated PLL allows zero-delay synthesis and skew management, making this part suited for distributing a clean reference clock across multiple loads on a PCB — think telecom line cards, baseband processors, or FPGA banks that need a synchronous fanout without adding separate PLLs per lane.
200 MHz maximum — what it means for the bus
The 200 MHz ceiling sets the upper speed grade for the output clocks. At this frequency the part can drive synchronous interfaces like DDR memory reference clocks, gigabit Ethernet MAC/PHY timing, or high-speed ADC/DAC sample clocks. The 4:18 ratio is the headline number — eighteen outputs from four inputs means one chip replaces multiple smaller fanout buffers, saving board area and reducing part count. The divider/multiplier block gives the designer flexibility to synthesize different output frequencies from a single input, though the outputs are all LVTTL and non-differential, so this part is not for differential pairs like LVPECL or LVDS fanout.
Lifecycle and compliance reality
This part is RoHS non-compliant, meaning it uses lead-bearing solder or other restricted substances.