KA339A

Overview

The KA339A is a quad analog comparator manufactured by Fairchild Semiconductor. It features four independent high-gain comparators designed for general-purpose applications. The device operates with a wide single power supply voltage range, typically from 2V to 36V, or dual supplies. It includes an open-collector output configuration, allowing flexible interfacing with various logic families. Key electrical characteristics include low input bias current and high common-mode rejection ratio, ensuring stable performance in diverse signal processing environments.

Feature Summary

• Integrates four independent high-gain comparators within a single package
• Supports wide single or dual power supply voltage operation
• Features open-collector outputs for versatile logic level compatibility
• Designed for general-purpose signal comparison and conditioning

Applications

• Over-voltage and under-voltage detection circuits
• Window comparator designs for threshold monitoring
• Simple oscillator and pulse generation circuits
• Level shifting and logic interface applications

Procurement Notes

Verify the specific manufacturer source, as Fairchild Semiconductor's semiconductor division was acquired by onsemi. Confirm whether the part number refers to legacy Fairchild stock or current onsemi production. Check datasheet revisions to ensure pinout and electrical specifications match the intended design requirements. Validate RoHS compliance status if required for the target market.

Selection Notes

Select this component when multiple independent comparisons are needed in a compact form factor. Consider the open-collector output requirement for pull-up resistor implementation. Evaluate the supply voltage range against the system's available power rails. Ensure the input common-mode voltage range accommodates the expected signal levels relative to the ground reference.

Part Context

The KA339 series belongs to a family of quad comparators widely used in industrial and consumer electronics. It serves as a functional equivalent to other industry-standard quad comparator ICs. The 'A' suffix typically denotes specific binning or temperature range variations compared to the base KA339 model. This component is part of the broader linear integrated circuit portfolio historically associated with Fairchild Semiconductor.

Replacement Considerations

Check for direct pin-compatible substitutes such as LM339 or MC339. Verify that alternative sources like onsemi offer the same electrical characteristics and package dimensions. Ensure any replacement maintains the open-collector output structure and supply voltage limits.