Texas Instruments ATL432LIBQDBZR

Overview

ATL432LIBQDBZR from Texas Instruments is a three-terminal adjustable shunt regulator with 0.5% reference voltage tolerance at 25°C, 2.5 V minimum output voltage, and operation across −40°C to +125°C (Q-temp grade). It sinks up to 15 mA cathode current with 0.3 Ω typical dynamic impedance and replaces Zener diodes in secondary-side regulation of flyback SMPS.

For engineers reviewing the ATL432LIBQDBZR datasheet, ATL432LIBQDBZR pinout, ATL432LIBQDBZR application, or ATL432LIBQDBZR equivalent, key selection considerations include its Q-temp automotive qualification, SOT-23-3 DBZ package pinout, low 80 µA minimum regulation current, and compatibility with precision voltage/current referencing and comparator-with-integrated-reference topologies.

Technical Context

The ATL432LIBQDBZR implements an internal 2.5 V bandgap reference and high-gain opamp driving a Darlington sink output stage. Its closed-loop regulation relies on external resistive feedback between cathode and reference pins to set output voltage from 2.5 V to 36 V.

In open-loop mode, it functions as a comparator with integrated reference, delivering fast response when supplied ≥80 µA cathode current. Its 0.3 Ω dynamic impedance and sharp turn-on characteristic enable stable operation without output capacitance in most configurations.

Key Specifications

Pinout & Package

ATL432LIBQDBZR is housed in a 3-pin SOT-23 (DBZ) package measuring 2.90 mm × 1.30 mm, optimized for space-constrained PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL432LIBQDBZR, ATL432LIBQDBZR reduces minimum cathode current by 20 µA-critical for battery-backed systems-while matching all other Q-temp specifications; versus ATL431LIBQDBZR, it offers identical performance with DBZ pin compatibility for TL432LI designs, avoiding layout changes.

Availability

ATL432LIBQDBZR is available at Aetrix Electronics and suitable for automotive power management, industrial voltage monitoring, and precision current sourcing requiring stable component supply across extended temperature ranges.

Supply support for ATL432LIBQDBZR 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 company designing analog ICs, embedded processors, and digital signal solutions for industrial, automotive, and communications markets.

The ATL43xLI product line delivers high-bandwidth, low-I_q programmable shunt regulators targeting precision voltage referencing, secondary-side SMPS regulation, and Zener replacement in safety-critical and thermally demanding applications.

FAQ

What is the pin configuration of ATL432LIBQDBZR?

ATL432LIBQDBZR uses a 3-pin SOT-23 (DBZ) package with pin 1 = CATHODE, pin 2 = REF, and pin 3 = ANODE. This pinout matches TL432LI and differs from ATL431LI, which swaps REF and CATHODE positions. The ANODE serves as the common reference node, and all voltages are specified relative to it.

Does ATL432LIBQDBZR require an output capacitor for stability?

No, ATL432LIBQDBZR is internally compensated and operates stably without a cathode-to-anode output capacitor in most configurations. However, if external capacitance is added for filtering, stability boundary charts in the datasheet (Figure 13–15) must be consulted to avoid oscillation-especially at cathode currents below 1 mA or with large capacitive loads.

What is the minimum cathode current needed for regulation in ATL432LIBQDBZR?

The maximum minimum cathode current (I_min) for ATL432LIBQDBZR is 80 µA at 25°C. This value increases slightly over temperature but remains ≤100 µA across the full −40°C to +125°C range. Supplying less than this prevents proper regulation and degrades open-loop gain, especially in comparator mode.

How does ATL432LIBQDBZR differ from ATL431LIBQDBZR?

ATL432LIBQDBZR and ATL431LIBQDBZR share identical electrical specifications, Q-temp rating, and B-grade tolerance-but differ in DBZ package pinout: ATL432LIBQDBZR has CATHODE/REF/ANODE (1/2/3), while ATL431LIBQDBZR has REF/ANODE/CATHODE (1/2/3). This makes ATL432LIBQDBZR a direct pin-compatible replacement for TL432LI, whereas ATL431LIBQDBZR requires PCB redesign.

Can ATL432LIBQDBZR be used as a comparator?

Yes, ATL432LIBQDBZR functions as a high-gain comparator with integrated 2.5 V reference when operated open-loop. It requires ≥80 µA cathode current to maintain sufficient gain; response speed improves with higher cathode current (e.g., 5 mA vs 0.1 mA). Output swings from ~2 V (low) to V_SUP (high), supporting logic-level interfacing with appropriate resistive scaling.