Diodes Incorporated AS431ANTR-G1

Overview

AS431ANTR-G1 from Diodes Incorporated is a three-terminal adjustable precision shunt regulator with 0.5% reference voltage tolerance, 2.5V to 36V programmable output, 1mA–100mA sink current capability, and guaranteed thermal stability from –40°C to +125°C. It replaces Zener diodes in switching power supplies, battery chargers, and precision voltage references where low temperature coefficient (20 ppm/°C typical) and sharp turn-on are required.

For engineers reviewing the AS431ANTR-G1 datasheet, AS431ANTR-G1 pinout, AS431ANTR-G1 application, or AS431ANTR-G1 equivalent, this device serves as a programmable 2.5V reference core with dynamic impedance of 0.15Ω (typ), low reference current (0.7µA typ), and stable operation under capacitive loads up to 100µF - critical for feedback loop integrity in isolated DC-DC converters and adapter designs.

Technical Context

The AS431ANTR-G1 implements a bandgap-based reference amplifier driving an NPN output stage, enabling precise cathode voltage regulation via external resistor divider between REF and CATHODE. Its functional block includes a high-gain error amplifier with internal 2.5V reference, low-noise design, and inherent immunity to cathode voltage variation (∆VREF/∆VKA ≤ –2.7 mV/V).

It operates in shunt mode with continuous cathode current control from 1mA to 100mA, supports stable regulation down to 0.4mA minimum cathode current, and maintains <4.5mV reference deviation over –40°C to +125°C - achieved through curvature-compensated bandgap architecture and optimized die layout for thermal tracking.

Key Specifications

Pinout & Package

SOT23-3 package: compact surface-mount outline with 2.3mm × 1.2mm footprint, 1.4mm height, and gull-wing leads; thermally optimized for PCB copper pour attachment on pin 3 (ANODE) to manage 370 mW power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBVR and KA431AZTA, the AS431ANTR-G1 provides tighter initial accuracy, lower temperature drift, and superior dynamic impedance - making it optimal for next-generation power adapters and automotive-grade chargers where long-term stability and minimal calibration overhead are critical.

Availability

AS431ANTR-G1 is available at Aetrix Electronics and suitable for switching power supplies, battery chargers, and precision voltage references requiring stable component supply, RoHS/Green compliance, and production continuity through 2030.

Supply support for AS431ANTR-G1 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing in China, Taiwan, and the U.S.

The AS431 belongs to Diodes' precision reference product line, engineered specifically for high-accuracy shunt regulation in cost-sensitive, space-constrained power management applications including consumer adapters, industrial PSUs, and automotive body electronics.

FAQ

What is the minimum cathode current required for regulation in AS431ANTR-G1?

The AS431ANTR-G1 requires a minimum cathode current of 0.4 mA to maintain regulation, verified per DS36599 Rev. 4-2 Section 5 (Electrical Characteristics). This low threshold enables stable operation even with high-value feedback resistors, reducing quiescent power in always-on adapter standby circuits.

Can AS431ANTR-G1 replace a standard Zener diode directly?

Yes - AS431ANTR-G1 functions as a 2-terminal Zener substitute when ANODE and REF pins are shorted, forming a 2.5V reference with far superior temperature stability (20 ppm/°C vs. 5000 ppm/°C for typical Zeners) and lower dynamic impedance (0.15Ω vs. 10–100Ω), but requires external resistors for voltages above 2.5V.

Is AS431ANTR-G1 qualified for automotive applications?

AS431ANTR-G1 is rated for –40°C to +125°C operating ambient temperature and meets AEC-Q200 stress test recommendations for passive components, though not formally AEC-Q100 qualified as an integrated circuit. It is widely deployed in automotive infotainment power rails and body control modules where extended temperature performance is mandatory.

What is the maximum power dissipation for AS431ANTR-G1 in SOT23 package?

In SOT23-3 package, AS431ANTR-G1 has a maximum power dissipation of 370 mW at TA = 25°C, based on θJA = 330°C/W and TJ(max) = 150°C. Derating is required above 25°C ambient: linear reduction of 3.7 mW/°C, reaching zero at +125°C ambient per DS36599 Absolute Maximum Ratings table.