Features and Benefits

  • UltraFast:
    • 4.5ns at 20mV Overdrive
    • 7ns at 5mV Overdrive
  • Low Power: 4mA per Comparator
  • Optimized for 3V and 5V Operation
  • Pinout Optimized for High Speed Ease of Use
  • Input Voltage Range Extends 100mV Below Negative Rail
  • TTL/CMOS Compatible Rail-to-Rail Outputs
  • Internal Hysteresis with Specified Limits
  • Low Dynamic Current Drain; 15µA/(V-MHz), Dominated by Load In Most Circuits
  • Tiny 3mm × 3mm × 0.75mm DFN Package (LT1720)

Product Details

The LT1720/LT1721 are UltraFast dual/quad comparators optimized for single supply operation, with a supply voltage range of 2.7V to 6V. The input voltage range extends from 100mV below ground to 1.2V below the supply voltage. Internal hysteresis makes the LT1720/LT1721 easy to use even with slow moving input signals. The rail-to-rail outputs directly interface to TTL and CMOS. Alternatively, the symmetric output drive can be harnessed for analog applications or for easy translation to other single supply logic levels.

The LT1720 is available in three 8-pin packages; three pins per comparator plus power and ground. In addition to SO and MSOP packages, a 3mm × 3mm low profile (0.8mm) dual fine pitch leadless package (DFN) is available for space limited applications. The LT1721 is available in the 16-pin SSOP and S packages.

The pinouts of the LT1720/LT1721 minimize parasitic effects by placing the most sensitive inputs (inverting) away from the outputs, shielded by the power rails. The LT1720/LT1721 are ideal for systems where small size and low power are paramount.


  • High Speed Differential Line Receiver
  • Crystal Oscillator Circuits
  • Window Comparators
  • Threshold Detectors/Discriminators
  • Pulse Stretchers
  • Zero-Crossing Detectors
  • High Speed Sampling Circuits

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Tools & Simulations


LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.


Models for the following parts are available in LTspice:


Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

PCN-PDN Information

Sample & Buy

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