CY23S081

The CY23S081 is a 3.3V zero delay buffer designed to distribute high-speed clocks in PC, workstation, datacom, telecom, and other high-performance applications.

The CY23S081 part has an on-chip PLL which locks to an input clock presented on the REF pin. The PLL feedback is required to be driven into the FBK pin, and can be obtained from one of the outputs. The input-to-output propagation delay is guaranteed to be less than 350 ps, and output-to-output skew is guaranteed to be less than 250 ps.

The CY23S081 has two banks of four outputs each, which can be controlled by the Select inputs as shown in Table 1. If all output clocks are not required, Bank B can be three-stated. The select inputs also allow the input clock to be directly applied to the output for chip and system testing purposes. The CY23S08 PLL enters a power-down state when there are
no rising edges on the REF input. In this mode, all outputs are three-stated and the PLL is turned off, resulting in less than 50 A of current draw. The PLL shuts down in two additional cases as shown in Table 1.

Multiple CY23S081 devices can accept the same input clock and distribute it in a system. In this case, the skew between the outputs of two devices is guaranteed to be less than 700 ps.

The CY23S08 is available in five different configurations, as shown in Table 2. The CY23S081 is the base part, where the output frequencies equal the reference if there is no counter in the feedback path. The CY23S081H is the high-drive version of the 1, and rise and fall times on this device are much faster. The CY23S082 allows the user to obtain 2X and 1X frequencies on each output bank. The exact configuration and output frequencies depends on which output drives the feedback pin. The CY23S082H is the high-drive version of the 2, and rise and fall times on this device are much faster. The CY23S083 allows the user to obtain 4X and 2X frequencies on the outputs.

The CY23S081 enables the user to obtain 2X clocks on all outputs. Thus, the part is extremely versatile, and can be used in a variety of applications.