MK5811S

Overview

The MK5811 is a low EMI clock generator IC designed to reduce electromagnetic interference in consumer applications. It utilizes a proprietary analog and digital Phase Locked Loop (PLL) technology to dither high-emission clocks, spreading the frequency spectrum and reducing amplitude peaks by 8 dB to 16 dB on odd harmonics. The device accepts a clock or crystal input ranging from 4 MHz to 32 MHz and provides a 1X frequency multiplication output within the same range. Operating at 3.3 V with an advanced low-power CMOS process, it supports centered and down spread configurations via tri-level select pins.

Feature Summary

• Generates low EMI output clock using PLL-based spread spectrum technology
• Accepts clock or crystal input; 1X frequency multiplication
• Input/Output frequency range: 4 MHz to 32 MHz
• Operating voltage: 3.0 V to 3.63 V
• Packaged in 8-pin SOIC

Applications

• Flat panel controllers
• Consumer electronics requiring EMI reduction

Procurement Notes

Verify component authenticity as the datasheet indicates End-of-Life (EOL) for non-green parts occurred on May 13, 2010. Ensure procurement of Pb-Free (LF) variants if RoHS compliance is required. Confirm package type availability between tubes and tape/reel options based on specific ordering suffixes.

Selection Notes

Select the MK5811 for fixed 1X frequency multiplication requirements. For different multiplier configurations, consider the MK5812 (2x) or MK5814 (4x). Configure spread direction and percentage using the S1, S0, and FRSEL tri-level pins. Ensure external decoupling capacitors are mounted close to VDD and GND pins without vias for optimal performance.

Part Context

The MK5811 is part of the IDT/ICS Low EMI Clock Generator family. It is functionally related to the MK5812 and MK5814, which offer 2x and 4x multiplication respectively. The datasheet recommends the MK5811A for new designs.

Replacement Considerations

For designs requiring different multiplication factors, the MK5812 (2x) and MK5814 (4x) are direct functional alternatives within the same family. The MK5811A is explicitly recommended as the successor for new designs.

FAQ

How is the spread spectrum configuration determined?

Spread direction and percentage are configured using the tri-level S1, S0, and FRSEL pins. Connecting these pins to GND, VDD, or leaving them floating selects specific center or down spread profiles.

What are the requirements for the external crystal?

The device requires a fundamental mode, parallel resonant crystal. External capacitors must be connected from X1 and X2 to ground, calculated based on the crystal's load capacitance (CL).

Can the Low EMI feature be disabled?

Yes, the Low EMI feature can be disabled by configuring the select pins to the 'No Spread' state (S1=M, S0=M).