DS1081LE+T

Overview

The DS1081LE+T is a spread-spectrum clock modulator IC designed to reduce electromagnetic interference (EMI) in digital electronic equipment. It accepts an input clock signal between 20MHz and 134MHz and delivers a center-dithered output using an integrated phase-locked loop (PLL). The device operates on a single 3.3V supply, consumes 15mA at maximum frequency, and features low cycle-to-cycle jitter of 75ps. Packaged in an 8-pin TSSOP, it supports selectable dither magnitudes from ±0.5% to ±2.0% and functions within an automotive temperature range of -40°C to +125°C.

Feature Summary

• Modulates input clocks from 20MHz to 134MHz with pin-selectable spread-spectrum dither magnitudes of ±0.5%, ±1.0%, ±1.5%, or ±2.0%.
• Integrated PLL generates center-dithered output with peak cycle-to-cycle jitter limited to 75ps.
• Configurable dither rate based on input frequency ranges via the CRSEL pin to optimize EMI reduction.
• SSEN pin allows for spread-spectrum enable/disable control and three-stating of the SSO output.

Applications

• LCD panels for TVs, desktop monitors, notebook PCs, and tablet PCs
• Automotive telematics and infotainment systems
• Printers

Procurement Notes

Verify that the ordering suffix 'T' corresponds to tape-and-reel packaging as specified in the manufacturer's documentation. Confirm the component meets lead-free and RoHS compliance requirements indicated by the '+' designation. Ensure the specific batch matches the -40°C to +125°C automotive temperature grade.

Selection Notes

Select this component when EMI reduction is required without altering clock rise/fall times or adding mechanical shielding. Ensure the system clock frequency falls within the 20MHz to 134MHz operational range. Verify that the power supply voltage remains between 3.0V and 3.6V and that the application environment accommodates the extended -40°C to +125°C temperature specification.

Part Context

The DS1081L series serves as a direct replacement for the Alliance/PulseCore Semiconductor P2040 series devices, offering pin compatibility. The 'E' suffix denotes the extended automotive temperature range (-40°C to +125°C), while the 'T' suffix indicates tape-and-reel packaging for automated assembly processes.

Replacement Considerations

The DS1081LE+T is pin-compatible with the Alliance/PulseCore Semiconductor P2040 series. Substitution should verify that the target device supports the same 20MHz to 134MHz input frequency range and 3.3V supply voltage constraints.

FAQ

How is the spread-spectrum dither magnitude selected?

The dither magnitude is selected via the SMSEL1 and SMSEL2 input pins, allowing configurations for ±0.5%, ±1.0%, ±1.5%, or ±2.0%.

What is the function of the SSEN pin?

The SSEN pin enables or disables spread-spectrum modulation and can three-state the SSO output when left open.

How is the dither rate determined?

The dither rate is determined by the input frequency (fIN) and configured via the CRSEL pin to ensure the rate remains above the audio frequency range.