Texas Instruments ATL431LIAIDQNR

Overview

ATL431LIAIDQNR from Texas Instruments is a high-bandwidth, low-quiescent-current programmable shunt voltage reference IC with 0.5% initial tolerance at 25°C, 2.5 V nominal reference voltage, and adjustable output from 2.5 V to 36 V. It operates across −40°C to +125°C (Q-temp grade), features 0.3 Ω typical dynamic impedance, and serves as a precision Zener replacement in secondary-side regulation of flyback SMPS.

For engineers reviewing the ATL431LIAIDQNR datasheet, ATL431LIAIDQNR pinout, ATL431LIAIDQNR application, or ATL431LIAIDQNR equivalent, key selection criteria include minimum cathode current (80 µA max), reference input current (0.4 µA max), temperature drift (27 mV max over Q-temp range), and compatibility with space-constrained designs using its 1.00 mm × 1.00 mm X2SON package.

Technical Context

The ATL431LIAIDQNR implements a three-terminal shunt regulator architecture with an internal 2.5 V bandgap reference and high-gain NPN-based error amplifier driving a Darlington sink output stage. Its open-loop comparator mode enables undervoltage/overvoltage monitoring, while closed-loop operation with external resistive feedback provides precise voltage or current regulation.

It achieves stable regulation without mandatory output capacitance due to internal compensation, supports cathode currents from 80 µA to 15 mA, and maintains sharp turn-on characteristics via active output circuitry-enabling reliable Zener diode replacement in automotive and industrial power systems requiring tight thermal stability.

Key Specifications

Pinout & Package

ATL431LIAIDQNR is packaged in a 4-pin X2SON (DQN) case measuring 1.00 mm × 1.00 mm with exposed thermal pad. This ultra-compact, surface-mount package supports high-density PCB layouts and enhanced thermal performance when the thermal pad is soldered to a ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt regulator applications.

Compared with TL431LIBPW and ATL431LIAIDBVR, ATL431LIAIDQNR delivers the tightest initial accuracy in the smallest package with the lowest minimum operating current-making it optimal for next-generation automotive power management where space, precision, and efficiency are jointly constrained.

Availability

ATL431LIAIDQNR is available at Aetrix Electronics and suitable for automotive power conversion, industrial voltage monitoring, and precision current sourcing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ATL431LIAIDQNR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of leadership in precision analog ICs and automotive-qualified components.

The ATL431LIAIDQNR belongs to TI's high-accuracy programmable shunt regulator product line, designed specifically for automotive and industrial systems demanding robust voltage referencing, low-power operation, and AEC-Q100-aligned reliability.

FAQ

What is the exact package type and dimensions of ATL431LIAIDQNR?

ATL431LIAIDQNR uses the X2SON (DQN) package: a 4-pin, 1.00 mm × 1.00 mm body with 0.35 mm height and exposed thermal pad. Pin 1 is ANODE, Pin 3 is CATHODE, Pin 4 is REF, and Pin 2 is NC. The thermal pad must be soldered to a PCB ground plane for optimal thermal performance and mechanical stability-confirmed in TI's SLVSDU6D datasheet Section 6 and Mechanical Drawing DQN.

Does ATL431LIAIDQNR require an external capacitor for stability?

No, ATL431LIAIDQNR is internally compensated and does not require an external output capacitor for basic stability. However, if a capacitor is added between CATHODE and ANODE, its value must be selected using TI's stability boundary charts (Figures 13–16 in SLVSDU6D) to avoid oscillation-especially under low-IKA conditions (<1 mA) or varying load capacitance. The device remains stable without any capacitor across its rated operating range.

What is the maximum cathode voltage rating for ATL431LIAIDQNR?

The absolute maximum cathode-to-anode voltage (VKA) for ATL431LIAIDQNR is 37 V, per Section 7.1 of the SLVSDU6D datasheet. The recommended operating range is VREF to 36 V. Exceeding 37 V risks permanent damage. This rating applies across the full −40°C to +125°C temperature range and is validated for automotive Q-temp qualification.

How does ATL431LIAIDQNR differ from ATL432LI variants?

ATL431LIAIDQNR and ATL432LI share identical electrical specifications-including 0.5% tolerance, 2.5 V reference, and Q-temp range-but differ in pinout. ATL431LIAIDQNR uses X2SON with ANODE–NC–CATHODE–REF ordering, while ATL432LI in DBZ (SOT-23) places REF on Pin 1 and NC on Pin 2. They are not pin-compatible; PCB layout and schematic symbols must match the specific variant. Both are functionally interchangeable when re-routed.

Can ATL431LIAIDQNR be used as a standalone voltage comparator?

Yes, ATL431LIAIDQNR functions as a comparator with integrated 2.5 V reference when operated open-loop: apply input to the REF pin, supply ≥80 µA cathode current, and monitor CATHODE as open-collector output. Its gain exceeds 10,000 V/V, enabling fast response (<10 µs) for overvoltage/undervoltage detection. Designers must ensure sufficient overdrive (>10% of VREF) and limit output voltage with pull-up resistors to avoid exceeding logic input ratings-details in Section 10.4.1 and Figure 23 of SLVSDU6D.