SL2305SI-1H

Clock Generators, PLLs, Frequency Synthesizers Overview

The SL2305SI-1H is a low skew, low jitter Zero Delay Buffer (ZDB) manufactured by Silicon Laboratories Inc. It generates up to five clock outputs from one reference input for high-speed distribution applications. The -1H suffix denotes the High-Drive version, supporting frequencies up to 140 MHz with a 15 pF load. Operating on a 3.3 V supply, it consumes 14 mA at 66 MHz and 26 mA at 133 MHz. Key electrical parameters include a maximum cycle-to-cycle jitter of 140 ps at 66 MHz, output-to-output skew of 150 ps, and product-to-product skew of 400 ps. It features SpreadThru™ PLL technology and enters power-down mode if the input is DC.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• High-drive output capability supports operation up to 140 MHz
• SpreadThru™ PLL passes modulated spread spectrum signals without degradation
• Low power dissipation with automatic shutdown in DC input states

Clock Generators, PLLs, Frequency Synthesizers Applications

• Printers and MFPs
• Digital Copiers
• PCs and Work Stations
• Routers, Switchers and Servers

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify that the component is sourced from authorized distributors or direct manufacturer channels to ensure authenticity. Confirm the specific package type matches the design requirements, as the device is available in both SOIC and TSSOP formats. Check for RoHS compliance status and verify the temperature grade corresponds to the intended operating environment before finalizing procurement.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the -1H variant when driving higher capacitance loads or requiring frequencies up to 140 MHz. Use the standard drive version for lower frequency applications up to 100 MHz to optimize EMI performance. Ensure all clock outputs are loaded equally to maintain specified skew values. Verify that the application does not require new designs, as this part is marked Not Recommended for New Designs.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component belongs to the SL2305 family of Zero Delay Buffers produced by Silicon Laboratories Inc. It is designed for clock distribution in digital systems requiring precise timing alignment. The device integrates an on-chip PLL that locks to the input clock and provides internal feedback via the CLKOUT pin to minimize delay between input and outputs.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Refer to the SL23EP05 for extended frequency operation ranging from 10 to 220 MHz and a wider power supply range of 2.5V to 3.3V. Evaluate alternative devices within the same family based on required drive strength and package configuration.

Clock Generators, PLLs, Frequency Synthesizers FAQ

How does the device handle a DC input signal?

If the input at CLKIN is DC (0 to VDD), the device detects this condition and forces all five outputs to a high-impedance state while turning off the PLL, resulting in a power consumption of less than 12 μA.

What is the function of the CLKOUT pin?

The CLKOUT pin serves as a buffered clock output and is used internally for feedback to the PLL. Adjusting the load capacitance on this pin relative to other outputs allows for zero-delay adjustment between the input and outputs.

Can the SL2305 process Spread Spectrum Clocking signals?

Yes, the device features SpreadThru™ PLL technology, which allows it to pass modulated Spread Spectrum Clock signals from the input to the outputs without degrading the spread percentage, profile, or modulation frequency.