LT1011IS8#TRPBF

Overview

The LT1011IS8#TRPBF is a general-purpose voltage comparator manufactured by Analog Devices Inc. It operates within a supply voltage range of 3V to ±18V and features an open-collector output capable of sourcing or sinking 50mA. The device guarantees a maximum input offset voltage of 0.5mV, a maximum input bias current of 25nA, and a maximum response time of 250ns. It provides a minimum large-signal voltage gain of 200,000 V/mV and maintains a common-mode rejection ratio of 94dB. The component is housed in an 8-lead plastic SO package and supports operation across a temperature range of -40°C to +85°C.

Feature Summary

• Pin compatible with LM111 series devices while offering significantly improved input characteristics including lower bias current and offset voltage.
• Features a floating transistor output that allows driving loads referenced to ground, negative supply, or positive supply up to 50V above the negative rail.
• Includes a strobe input pin to force the output transistor into an off state, providing a high output at the collector.
• Capable of fully specified DC parameters and response time when operating on a single 5V supply.

Applications

• SAR A/D Converters
• Voltage-to-Frequency Converters
• Precision RC Oscillators
• Peak Detectors
• Motor Speed Control

Procurement Notes

Verify the specific suffix #TRPBF indicates tape and reel packaging rather than tube packaging. Confirm the IS8 designation corresponds to the industrial temperature grade (-40°C to +85°C) and the SOIC-8 package type. Ensure compatibility with existing board layouts designed for LM111 equivalents if cross-referencing is required.

Selection Notes

Select this component when higher precision and speed are required compared to standard LM111 alternatives. It is suitable for applications requiring low input bias current and guaranteed offset voltage drift. Consider the open-collector output topology for flexible load referencing. Verify that the 50mA output current capability meets the drive requirements of the connected circuitry.

Part Context

The LT1011 is part of the LT1011/LT1011A family of voltage comparators from Analog Devices. It was designed to replace the LM111 with enhanced performance metrics. The IS8 variant specifically denotes the industrial temperature range and surface-mount SOIC packaging. This family is known for its versatility in general-purpose comparison tasks.

Replacement Considerations

LM111 series devices are pin-compatible but offer inferior electrical specifications. LM111H/NOPB is listed as a substitute for other variants in the family. Verify functional equivalence regarding strobing and balance pin operations when substituting.

FAQ

How does the LT1011 handle large differential input voltages?

The inputs can tolerate differential voltages up to the full supply voltage, even with ±18V supplies, allowing them to be clamped to the supplies with simple diode clamps without damage.

What is the function of the Balance/Strobe pin (Pin 6)?

Pin 6 serves as the Strobe input to force the output transistor off, or as a Balance input for offset adjustment and hysteresis addition. If neither function is used, it should be connected to Pin 5 with a capacitor.

Can the LT1011 operate with a single 5V supply?

Yes, the LT1011 is fully specified for DC parameters and response time when operating on a single 5V supply.