Microchip MCP6542-E/SN Dual General-Purpose Comparator: Datasheet, Features, and Application Circuits

The Microchip MCP6542-E/SN is a dual, push-pull output comparator renowned for its ultra-low power consumption and wide operating voltage range, making it an ideal choice for a vast array of general-purpose and battery-powered applications. Housed in a compact SOIC-8 package, this comparator combines performance with space efficiency.

This article delves into the key specifications from its datasheet, highlights its standout features, and explores practical application circuits.

Datasheet Overview and Key Specifications

The MCP6542 is part of the MCP6541/2/4 family. Key absolute maximum ratings and operating conditions include:

Supply Voltage Range (VDD): 1.6V to 5.5V

Input Voltage Range: -0.3V to VDD + 0.3V

Quiescent Current (Typical): Extremely low at 900 nA per comparator

Input Bias Current (Typical): 1 pA

Propagation Delay: Varies with supply voltage (e.g., ~4.5 µs at 5V)

Output Type: CMOS Push-Pull, which allows for rail-to-rail output swing and eliminates the need for an external pull-up resistor required by open-drain outputs.

Operating Temperature Range (E-grade): -40°C to +125°C

Salient Features

The MCP6542-E/SN offers a compelling set of features designed for modern electronic design:

Ultra-Low Quiescent Current: Consumption of less than 1 µA per comparator dramatically extends battery life in portable devices.

Single-Supply, Rail-to-Rail Input: The device operates from a single supply as low as 1.6V. The input common-mode voltage range extends 200 mV beyond both supply rails (VSS and VDD), enabling easy interface with sensors and signals that swing close to the power rails.

CMOS Push-Pull Output: Provides a strong drive capability to both supply rails, simplifying logic interface and improving switching speed for capacitive loads.

Enhanced Immunity to Shoot-Through Current: The internal design minimizes supply current spikes during output transitions, reducing noise on the power supply.

Industrial Temperature Range (E-grade): The "E" suffix guarantees operation across the industrial temperature range of -40°C to +125°C, making it suitable for automotive, industrial, and harsh environments.

Application Circuits

The versatility of the MCP6542 allows it to be deployed in countless circuits. Here are two common examples:

1. Window Comparator Circuit:

This circuit monitors whether a sensor voltage (VIN) stays within a predefined "window" defined by two reference voltages (VREF_HIGH and VREF_LOW). One comparator checks if VIN is above VREF_LOW, and the other checks if VIN is below VREF_HIGH. The outputs can be combined using logic to generate a single digital signal that indicates an out-of-bounds condition, perfect for over-voltage and under-voltage protection systems or alarm triggers.

2. Light Sensor Interface with Hysteresis:

A photodiode or phototransistor generates a current proportional to light intensity, which is converted to a voltage. One half of the MCP6542 can be configured as a Schmitt trigger by adding positive feedback with a resistor network. This hysteresis creates two distinct switching thresholds, preventing the output from oscillating when the input light level slowly changes near the trigger point. This provides a clean, chatter-free digital signal to a microcontroller.

ICGOODFIND Summary

The Microchip MCP6542-E/SN stands out as an exceptionally efficient and robust dual comparator solution. Its defining characteristics of ultra-low power consumption, wide single-supply operation, and rail-to-rail input capability make it a superior choice for design engineers focused on power sensitivity and signal integrity. Its push-pull output stage offers simplicity and performance, solidifying its role as a fundamental component in portable, automotive, industrial, and consumer applications.

Keywords:

Low-Power Comparator

Push-Pull Output

Rail-to-Rail Input

Window Detector

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