KA431DTF

Overview

The KA431DTF is a programmable shunt voltage regulator manufactured by onsemi. It functions as a precision reference and error amplifier, utilizing an internal 2.5V bandgap reference to regulate output voltage via an external resistor divider. The device operates within a cathode current range of 1mA to 100mA and supports a supply voltage range from 2.5V to 36V. It features low dynamic impedance and high bandwidth for stable feedback loop performance. The component is housed in a compact SOT-23 surface-mount package, suitable for space-constrained designs requiring precise voltage regulation.

Feature Summary

• Integrates a precision 2.5V bandgap voltage reference with a high-gain operational amplifier for accurate error sensing.
• Enables adjustable output voltage setting through external resistive dividers connected to the reference pin.
• Provides low dynamic output impedance to maintain regulation stability under varying load conditions.

Applications

• Precision voltage references in power supply circuits
• Error amplifiers in switching mode power supplies (SMPS)
• Battery chargers requiring accurate voltage monitoring

Procurement Notes

Verify the specific suffix 'DTF' against the manufacturer's official datasheet to confirm the exact tape-and-reel packaging quantity and marking codes. Ensure the procurement source provides documentation confirming RoHS compliance and material declarations consistent with onsemi standards. Cross-reference the date code and lot traceability requirements with your quality assurance protocols before finalizing orders.

Selection Notes

Select this component when a low-cost, high-precision shunt regulator is required for feedback loops or reference generation. Consider the thermal performance and maximum cathode current limits relative to the expected dissipation in the application. Evaluate the need for the specific SOT-23 footprint and ensure the operating voltage range aligns with the system's supply rails.

Part Context

The KA431 series belongs to a family of programmable shunt regulators widely used in analog control applications. These devices serve as alternatives to Zener diodes, offering superior accuracy and temperature stability. The KA431 variant specifically integrates the reference and amplifier on a single monolithic chip, simplifying circuit design compared to discrete solutions while maintaining industry-standard pinouts for easy replacement.

Replacement Considerations

Compatible substitutes include the TL431 and LM431, which share identical electrical characteristics and pin configurations. Verify that any alternative part meets the same AEC-Q101 qualification if automotive reliability is required. Confirm that the replacement device offers equivalent dynamic impedance and bandwidth specifications to ensure loop stability in existing designs.