MAX9021AXK

Overview

The MAX9021AXK is a single-channel analog comparator from the Maxim Integrated MAX9021 series, designed for low-power portable applications. It operates on a single supply voltage ranging from 2.5V to 5.5V or dual supplies of ±1.25V to ±2.75V. The device consumes only 2.8µA of supply current per comparator and features a typical propagation delay of 3µs. It includes internal 4mV hysteresis for noise immunity and supports rail-to-rail output swing. The input common-mode range extends from the negative supply to within 1.1V of the positive supply. It is housed in a space-saving 5-pin SC70 package.

Feature Summary

• Ultra-low power consumption optimized for battery-operated systems
• Internal 4mV hysteresis prevents oscillation with slow-moving signals
• Rail-to-rail output capability ensures full logic level compatibility
• No phase reversal occurs even when inputs are overdriven

Applications

• Battery-powered portable systems
• Sensor-signal detection circuits
• Digital line receivers
• Threshold detectors and discriminators

Procurement Notes

Verify the specific suffix 'AXK' against the manufacturer's official datasheet to confirm the exact package type (SC70) and temperature grade. Ensure the ordering part number matches the required tape-and-reel quantity if applicable. Cross-reference the manufacturer code to distinguish between Analog Devices and Maxim Integrated legacy branding. Confirm RoHS compliance status through the official component documentation before procurement.

Selection Notes

Select this component when design constraints require minimal static current draw alongside a compact footprint. The built-in hysteresis eliminates the need for external feedback resistors in noisy environments. Verify that the 3µs propagation delay meets the system timing requirements. Ensure the operating voltage remains within the 2.5V to 5.5V range to maintain specified performance characteristics.

Part Context

The MAX9021AXK belongs to the MAX9021/MAX9022/MAX9024 family of micropower comparators. This series is engineered for space-sensitive designs where power efficiency is critical. The single-channel configuration distinguishes it from the dual (MAX9022) and quad (MAX9024) variants, offering a tailored solution for applications requiring only one comparator channel in an ultra-small package.

Replacement Considerations

The MAX9021AUK is a pin-compatible alternative within the same series. Verify electrical parameters such as propagation delay and supply current match the design requirements. Check package dimensions to ensure mechanical fit in the existing PCB layout.