ADCMP391ARZ

Overview

The ADCMP391ARZ is a single-channel analog comparator manufactured by Analog Devices Inc. It operates on a single supply voltage ranging from 2.3 V to 5.5 V and features rail-to-rail common-mode input voltage capability extending 200 mV beyond the rails. The device guarantees a defined logic low output state during power-up when the supply voltage is below the undervoltage lockout threshold. It consumes a typical quiescent current of 18.6 µA and maintains an input offset voltage of 1 mV typical across the full common-mode range. The component is housed in an 8-lead narrow body SOIC package and supports operation over an extended temperature range from −40°C to +125°C.

Feature Summary

• Features a known power-up state that asserts a logic low output until the supply voltage exceeds the undervoltage lockout threshold.
• Supports rail-to-rail common-mode input voltage with a typical offset voltage of 1 mV across the entire operating range.
• Operates efficiently with minimal supply current consumption, making it suitable for battery-powered applications.

Applications

• Battery management and monitoring systems
• Power supply detection circuits
• Window comparators for voltage supervision
• Threshold detectors and discriminators
• Microprocessor system interfaces

Procurement Notes

Verify the specific ordering suffix to confirm packaging format. The ARZ designation indicates RoHS compliance. Confirm the package type matches the design requirements, as variants exist in tube or reel formats. Ensure the selected part number aligns with the required temperature range and pin configuration for the target application.

Selection Notes

Select this component for general-purpose comparison tasks requiring rail-to-rail inputs and low power consumption. The open-drain output necessitates an external pull-up resistor to define the high logic level. Consider the propagation delay characteristics relative to the input overdrive voltage and load capacitance when designing timing-critical circuits.

Part Context

This device belongs to the ADCMP391 series of single-supply comparators. It is designed for applications where low voltage operation and precise threshold detection are critical. The series offers a compact footprint suitable for space-constrained designs while maintaining robust performance across wide temperature variations.

Replacement Considerations

The ADCMP391ARZ-RL7 serves as a direct functional replacement, differing only in the reel packaging format compared to the tube packaging of the standard ARZ variant. Both share identical electrical specifications and pin configurations.

FAQ

What is the behavior of the output during power-up?

The ADCMP391 guarantees a logic low output state when the supply voltage is below the undervoltage lockout threshold. Once the voltage exceeds this threshold, the comparator inputs take control of the output state.

How does the rail-to-rail input feature benefit the circuit?

The rail-to-rail input allows the common-mode voltage to extend up to 200 mV beyond the supply rails. This eliminates the restriction found in single differential pair stages, enabling accurate comparison even at low supply voltages.