TL431AIDMR2G

Overview

The TL431AIDMR2G is a three-terminal programmable shunt regulator diode from onsemi, housed in an 8-pin Micro8 package. It operates as a low temperature coefficient zener reference, programmable from the internal Vref of 2.495 V up to 36 V using two external resistors. The device supports a wide operating current range of 1.0 mA to 100 mA with a typical dynamic impedance of 0.22 Ω. It features a voltage reference tolerance of ±1% and a full-range temperature coefficient of 50 ppm/°C. The component functions effectively as a positive or negative voltage reference and is rated for an ambient temperature range of -40 °C to +85 °C.

Feature Summary

• Programmable output voltage capability extending from the internal reference level up to 36 V via external resistor networks.
• Temperature compensated operation designed to maintain stability across the full rated operating temperature range.
• Low dynamic output impedance characteristic suitable for precision regulation applications.
• Internal circuitry provides latch-up protection exceeding standard JEDEC limits.

Applications

• Feedback control loops driving optocouplers in power supply designs
• Digital voltmeter reference circuits
• Op amp circuitry requiring stable biasing
• Constant current source implementations

Procurement Notes

Verify the specific suffix 'DM' corresponds to the Micro8 package variant when sourcing replacements. Confirm that the 'A' designation aligns with the required ±1% initial accuracy tolerance for the target design. Ensure the ordering code matches the tape and reel shipping format if automated assembly is utilized. Cross-reference the RoHS compliance status with current environmental regulations applicable to the deployment region.

Selection Notes

Select this component when a precise, adjustable shunt reference is needed within the -40 °C to +85 °C industrial temperature window. The Micro8 package offers a compact footprint suitable for space-constrained printed circuit board layouts. Consider the 1.0 mA minimum cathode current requirement to ensure proper regulation during low-load conditions. Evaluate the 0.22 Ω typical dynamic impedance against the noise sensitivity requirements of the analog section.

Part Context

This device belongs to the TL431 family of programmable precision references manufactured by onsemi. The family includes variants with different tolerances (B series) and extended temperature ranges (NCV/SCV prefixes). The TL431A specifically denotes the 1% tolerance grade. The Micro8 package is an internally modified SOIC-8 structure where pins are electrically common to the die attach flag to enhance thermal dissipation capabilities.

Replacement Considerations

TL431ACDMR2G

FAQ

How is the output voltage programmed?

The output voltage is set between Vref and 36 V using a voltage divider network consisting of two external resistors connected between the cathode, reference pin, and anode.

What is the minimum cathode current required for regulation?

The device requires a minimum cathode current of 1.0 mA to maintain proper regulation characteristics.