ICS341MP

Clock Generators, PLLs, Frequency Synthesizers Overview

The ICS341MP is a single-output, field-programmable clock synthesizer from the VersaClock family. It generates output frequencies between 250 kHz and 200 MHz using an M/N multiplier PLL (M=1-2048, N=1-1024). The device supports spread spectrum modulation up to 4% to reduce EMI. It operates on a 3.3 V supply (3.15 V–3.45 V) with a typical current of 11 mA at 33.3333 MHz output. It accepts crystal inputs (5–27 MHz) or external clocks (2–50 MHz). The component is housed in an 8-pin SOIC package and includes four OTP ROM locations for configuration storage.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Field programmability via IDT VersaClock software with four selectable OTP ROM configurations
• Spread spectrum capability with center or down spread modes up to 4% total deviation
• Modulation rates selectable between 32 kHz and 120 kHz
• Power-down feature that tri-states outputs and disables PLLs when PDTS pin is low

Clock Generators, PLLs, Frequency Synthesizers Applications

• Replacing multiple crystals and oscillators to save board space
• Systems requiring reduced electromagnetic interference (EMI)
• Driving down-circuit PLLs or Zero Delay Buffers
• Applications adhering to PCI standards

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific suffix against the ordering table: 'P' indicates tube packaging, while 'PT' indicates tape and reel. The 'LF' suffix denotes lead-free/RoHS compliance. Confirm the temperature grade ('M' for commercial 0°C to +70°C vs 'MI' for industrial -40°C to +85°C) matches the design requirements before procurement.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the ICS341MP when a single LVCMOS output is sufficient; use the ICS342 for dual outputs or the ICS343 for triple outputs. Ensure the input reference frequency falls within the specified ranges: 5–27 MHz for crystals or 2–50 MHz for external clocks. Verify that the required output frequency can be synthesized within the M/N multiplier limits without exceeding jitter specifications.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The ICS341MP is part of the IDT/ICS VersaClock series, which utilizes One-Time Programmable (OTP) ROM for field configurability. This allows users to customize frequency and spread settings post-manufacturing. The device is designed to replace discrete crystal oscillators, consolidating timing generation into a single integrated circuit.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

For identical functionality with different packaging, consider the ICS341MPT (tape and reel) or ICS341MPLF (lead-free tubes). For multi-output requirements, the ICS342 (dual output) and ICS343 (triple output) are direct architectural successors within the same family.

Clock Generators, PLLs, Frequency Synthesizers FAQ

What is the difference between center spread and down spread modes?

Center spread modulates the frequency equally above and below the target frequency, keeping the average equal to the target. Down spread modulates only below the target frequency, ensuring the maximum frequency does not exceed the target rating.

How is the device powered down?

Taking the PDTS pin low powers down the entire chip, tri-stating the CLK output and turning off the PLLs.

What are the recommended PCB layout guidelines for the crystal input?

The external crystal should be mounted next to the device with short traces. X1 and X2 traces should be separated and kept away from other signal traces to minimize noise and stray capacitance.