LT1394IS8#PBF

Overview

The LT1394IS8#PBF is a high-speed, low-power comparator featuring complementary outputs and an internal latch. It operates from single 5V or dual ±5V supplies with a propagation delay of 7ns (max 9ns at -40°C to 85°C). The device offers a typical input offset voltage of 0.8mV and draws 6mA supply current. Input common mode range extends to the negative rail, allowing ground sensing. Outputs are TTL/CMOS compatible, providing direct drive for logic families.

Feature Summary

• Complementary CMOS/TTL outputs enable direct interface with standard logic families without level shifting.
• Internal latch capability retains output data when the LATCH pin is asserted, simplifying digital interfacing.
• Input common mode range extends to the negative supply rail, supporting ground-sensing applications on single supplies.
• Stable operation with slow input signals eliminates the need for minimum slew rate specifications.

Applications

• High speed analog-to-digital converter front-ends
• Zero-crossing detectors
• Current sense circuits for switching regulators
• Fast pulse height and width discriminators

Procurement Notes

Verify the IS8 suffix indicates the industrial temperature range (-40°C to 85°C) and SOIC-8 package. Confirm RoHS compliance and lead-free status via the manufacturer's latest documentation. Ensure ordering codes match the specific tape-and-reel or tube packaging requirements for your assembly process.

Selection Notes

Select this component for applications requiring fast response times with low power consumption. The complementary outputs simplify logic interfacing compared to open-collector devices. Consider the internal latch feature if signal retention during sampling is required. Verify that the input signal levels remain within the specified common mode range relative to the chosen supply configuration.

Part Context

The LT1394 belongs to Analog Devices' UltraFast comparator family, designed for precision and speed in single-supply environments. It shares pin compatibility with legacy parts like the LT1016 and LT1116, facilitating upgrades in existing designs. The IS8 variant specifies the extended temperature range and plastic SOIC packaging.

Replacement Considerations

LT1394CS8#PBF: Commercial temperature range (0°C to 70°C), same package and electrical specs.

FAQ

Can the LT1394 inputs exceed the positive supply voltage?

Yes, either input may go above the positive supply limit without damage, provided the current does not exceed 10mA through the internal diode.

What is the function of the LATCH ENABLE pin?

When held high, the LATCH ENABLE pin retains the current output state regardless of subsequent input changes, holding data until the pin is deasserted.