LT1720CMS8#TRPBF

Overview

The LT1720CMS8#TRPBF is a dual ultrafast comparator from Analog Devices, housed in an 8-lead plastic MSOP package. It operates on a single supply voltage ranging from 2.7V to 6V. The device features rail-to-rail outputs compatible with TTL and CMOS logic levels. Electrical specifications include a propagation delay of 4.5ns at 20mV overdrive and 7ns at 5mV overdrive. Quiescent power consumption is 4mA per comparator at 5V. The input common-mode voltage range extends from 100mV below ground to 1.2V below the positive supply rail.

Feature Summary

• Rail-to-rail output stage enables direct interfacing with standard digital logic families.
• Internal hysteresis simplifies circuit design for slow-moving input signals.
• Input voltage range extends 100mV below the negative supply rail.
• Pinout configuration minimizes parasitic effects by shielding sensitive inputs.

Applications

• Crystal oscillator circuits
• High-speed differential line receivers
• Window comparators
• Threshold detectors and discriminators

Procurement Notes

Verify that the component matches the specific C-grade temperature rating (0°C to 70°C) required for the application environment. Confirm the MSOP-8 package dimensions align with PCB footprint constraints. Ensure the datasheet revision corresponds to the manufacturing batch for accurate electrical parameter validation.

Selection Notes

Select this component when high speed and low power are critical within a single-supply system. The internal hysteresis reduces the need for external components compared to other comparators. Consider the 2.7V minimum supply voltage if operating near battery depletion levels. The dual-channel architecture saves board space compared to using two single-channel devices.

Part Context

This part belongs to the LT1720/LT1721 UltraFast comparator family. The LT1720 variant provides dual channels, whereas the LT1721 offers quad channels. Both share identical electrical characteristics and pinouts for their respective channel counts. The family is optimized for applications requiring fast response times with minimal power consumption.

Replacement Considerations

LT1720CS8#TRPBF: Identical function in SO-8 package.

FAQ

How does the internal hysteresis affect the trip points?

The internal hysteresis creates distinct upper and lower trip points. The offset voltage is defined as the average of these two points, while the hysteresis voltage is the difference between them.

What happens if both inputs go above the positive common mode limit?

The input stage becomes debiased and the output polarity may become random. However, the internal hysteresis maintains the output at a valid logic level until inputs return to the common mode range.