LT1018

LT1018 Micropower Dual Comparator

Overview

The LT1018 is a general-purpose micropower dual comparator designed for low-power and high-performance applications. It is part of the LT1017/LT1018 series, with the LT1018 optimized for higher speed and slightly higher power consumption compared to the LT1017. The device operates over a wide voltage range, from a single 1.1V cell up to 40V, making it suitable for battery-powered and high-voltage applications. The output stage incorporates a class "B" pull-up current source, eliminating the need for an external resistive pull-up, which reduces power dissipation and simplifies circuit design.

Features

• Micropower Operation: Low quiescent current makes it ideal for battery-powered applications.
• Wide Supply Voltage Range: Operates from 1.1V to 40V, accommodating diverse power sources.
• Class "B" Output Stage: Integrated pull-up current source removes the need for external resistors, saving power and board space.
• High-Speed Performance: Faster response time compared to the LT1017, suitable for time-critical applications.
• Flexible Output Configuration: Output can drive loads connected to a supply more positive than the comparator itself.
• Low Input Bias Current: Minimizes errors in precision applications.
• Dual Comparator Design: Two independent comparators in a single package, reducing component count.
• Robust Construction: Designed for reliable operation in industrial and automotive environments.

Applications

• Battery-Powered Systems: Ideal for portable electronics due to low power consumption.
• Voltage Monitoring: Used in power supply supervision and undervoltage/overvoltage detection circuits.
• Window Comparators: Suitable for creating voltage window detection systems.
• Signal Conditioning: Used in sensor interfaces and analog signal processing.
• Industrial Control Systems: Provides reliable switching in automation and control circuits.
• Automotive Electronics: Operates reliably in harsh automotive environments.
• Consumer Electronics: Used in devices requiring low-power comparators, such as wearables and IoT gadgets.

Electrical Characteristics

The LT1018 exhibits the following key electrical specifications under typical operating conditions (unless otherwise noted):

• Supply Voltage Range: 1.1V to 40V
• Quiescent Current (per Comparator): 20µA (typical) at 5V
• Input Offset Voltage: 2mV (max) at 25°C
• Input Bias Current: 25nA (typical) at 25°C
• Response Time (10mV Overdrive): 3µs (typical)
• Output Saturation Voltage: 250mV (typical) at 5mA sink current
• Output Current Source: 1mA (typical)
• Common-Mode Input Range: Ground to V+ - 1.5V
• Operating Temperature Range: -40°C to +85°C (industrial grade)

Package Information

The LT1018 is available in multiple package options to suit different application requirements:

• 8-Lead PDIP (Plastic Dual In-Line Package):
  • Package Code: N8
  • Dimensions: 9.81mm x 6.35mm (typical)
  • Pin Pitch: 2.54mm
• 8-Lead SOIC (Small Outline Integrated Circuit):
  • Package Code: SO-8
  • Dimensions: 4.90mm x 3.90mm (typical)
  • Pin Pitch: 1.27mm
• 8-Lead MSOP (Mini Small Outline Package):
  • Package Code: MS8
  • Dimensions: 3.00mm x 3.00mm (typical)
  • Pin Pitch: 0.65mm

Detailed Description

The LT1018 is a versatile dual comparator designed for applications requiring low power consumption and high performance. Its wide supply voltage range allows it to be used in systems powered by single-cell batteries or higher-voltage industrial supplies. The integrated class "B" output stage simplifies design by eliminating the need for external pull-up resistors, while also improving power efficiency.

The device features low input bias current and offset voltage, ensuring accurate comparisons in precision circuits. The dual-comparator configuration provides flexibility for designs requiring multiple comparison functions, such as window detectors or level shifters. The robust construction ensures reliable operation across a wide temperature range, making it suitable for industrial and automotive applications.

Typical Application Circuit

A common application for the LT1018 is a voltage monitor circuit. Below is a simplified example:

• Components:
  • LT1018 Dual Comparator
  • Voltage Reference (e.g., 2.5V)
  • Resistive Divider Network
  • Load Resistor (if driving external logic)
• Operation: The resistive divider sets a threshold voltage for comparison. When the input voltage crosses this threshold, the comparator output switches, signaling an overvoltage or undervoltage condition.

Conclusion

The LT1018 micropower dual comparator is a highly flexible and efficient component suitable for a wide range of applications, from portable electronics to industrial systems. Its combination of low power consumption, wide voltage range, and integrated features makes it an excellent choice for designers seeking reliable performance in space- and power-constrained environments.