SL2309SC-1

Clock Generators, PLLs, Frequency Synthesizers Overview

The SL2309SC-1 is a low skew, low jitter Zero Delay Buffer (ZDB) designed for high-speed clock distribution. It accepts one reference input and drives nine outputs organized as two banks of four plus one feedback output. Operating at 3.3V, the standard drive version supports frequencies up to 100 MHz with a 15 pF load. Key electrical parameters include a maximum cycle-to-cycle jitter of 150 ps, output-to-output skew of 150 ps, and product-to-product skew of 400 ps. The device operates within a commercial temperature range of 0°C to 70°C and is housed in a 16-pin SOIC package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Zero-delay buffering capability using an on-chip PLL that locks to the reference input.
• SpreadThru™ feature allows direct pass-through of modulated Spread Spectrum Clock signals without degradation.
• Configurable select inputs enable bypassing the PLL or tri-stating specific output banks to reduce power consumption.

Clock Generators, PLLs, Frequency Synthesizers Applications

• Printers and Multi-Function Printers (MFPs)
• Digital Copiers
• PCs and Workstations
• Digital Television (DTV)
• Routers, Switchers, and Servers

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific ordering suffix to confirm package type and temperature grade. The 'SC' suffix indicates a 16-pin SOIC package, while 'ZI' or 'ZC' indicate TSSOP options. Suffixes '-1' denote standard drive, whereas '-1H' denotes high drive. Confirm RoHS compliance status and check for 'Not Recommended for New Designs' notices before finalizing procurement plans.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the standard drive (-1) version for applications requiring frequencies up to 100 MHz with lower EMI. Choose the high-drive (-1H) variant if operation up to 140 MHz is required or if higher load capacitance needs to be driven. Ensure external loading on CLKOUT matches Bank A and B loads to maintain zero delay specifications. Verify thermal requirements against the junction-to-ambient resistance values provided in the datasheet.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component belongs to the SL23xx family of low-power, low-jitter clock buffers manufactured by Silicon Laboratories. It serves as a clock distribution solution for systems requiring precise timing alignment between multiple peripherals. The SL2309 specifically provides nine outputs from a single reference, distinguishing it from lower-channel variants like the SL2305.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Publicly confirmed substitutes include the CY2309 series from Cypress Semiconductor and the ASM5P2309A from ON Semiconductor. These parts share similar zero-delay buffer architectures and pinout configurations but may differ in drive strength, jitter performance, and operating frequency ranges. Verify electrical compatibility before substitution.

Clock Generators, PLLs, Frequency Synthesizers FAQ

How does the SL2309 handle Spread Spectrum Clocking (SSC)?

The device features a SpreadThru™ PLL that passes the modulated SSC signal from the reference input to the output clocks without degrading the spread percentage, profile, or modulation frequency.

What is the function of the CLKOUT pin?

The CLKOUT pin provides a buffered output of the internal PLL feedback signal. It is used internally for PLL locking and externally to match the load capacitance of other outputs to achieve zero input-to-output delay.

How can the output power dissipation be reduced?

Power dissipation can be reduced by using the select inputs (S1 and S2) to tri-state unused output banks. For example, setting S1=0 and S2=0 tri-states both Bank A and Bank B outputs while keeping the PLL active.