Diodes Incorporated AS431BNTR-G1

Overview

AS431BNTR-G1 from Diodes Incorporated is a three-terminal adjustable precision shunt regulator with 1.0% reference voltage tolerance, 2.5V to 36V programmable output, 0.15Ω typical dynamic impedance, and operation from –40°C to +125°C. It replaces Zener diodes in switching power supplies, battery chargers, and precision voltage references where thermal stability and low output noise are critical.

For engineers reviewing the AS431BNTR-G1 datasheet, AS431BNTR-G1 pinout, AS431BNTR-G1 application, or AS431BNTR-G1 equivalent, key selection criteria include cathode current range (1–100 mA), temperature coefficient (20 ppm/°C typical), reference voltage deviation (≤16 mV over –40°C to +125°C), and SOT23 package compatibility with high-density PCB layouts.

Technical Context

The AS431BNTR-G1 implements a bandgap-based precision reference core with sharp turn-on characteristics and low output impedance, enabling stable regulation under capacitive loads up to 100 µF without oscillation. Its internal architecture supports sink-current operation only, with no active pull-up or driver stages.

It operates as a two-node control element: the REF pin senses voltage via external resistor divider, while the CATHODE carries regulated sink current; ANODE serves as the return path. No internal compensation is required-stability is maintained across load capacitance from 0 to 100 µF at cathode voltages of 5 V, 10 V, and 15 V.

Key Specifications

Pinout & Package

SOT23-3 package: small-outline transistor outline with gull-wing leads, 2.3 mm × 1.4 mm footprint, 1.1 mm height, RoHS-compliant and halogen-free "Green" molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431BIDBVR and KA431AZTA, AS431BNTR-G1 delivers superior thermal stability (20 ppm/°C vs. 34–50 ppm/°C), lower dynamic impedance (0.15 Ω vs. ≥0.2 Ω), and halogen-free "Green" compliance-making it optimal for compact, thermally constrained, and environmentally regulated applications.

Availability

AS431BNTR-G1 is available at Aetrix Electronics and suitable for switching power supplies, battery chargers, and precision voltage monitoring systems requiring stable component supply, long-term lifecycle support, and RoHS 3/Green compliance.

Supply support for AS431BNTR-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, specializing in high-reliability power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

The AS431 belongs to Diodes' precision reference product line, designed specifically for high-stability, low-drift shunt regulation in space-constrained and thermally demanding power systems.

FAQ

What is the minimum cathode current required for regulation in AS431BNTR-G1?

The AS431BNTR-G1 requires a minimum cathode current of 0.4 mA to maintain regulation, with typical operation starting at 1.0 mA. Below this threshold, reference voltage accuracy degrades significantly, and the device may exit regulation-designs must ensure external bias networks guarantee ≥1 mA under all operating conditions.

Can AS431BNTR-G1 replace a standard Zener diode directly?

Yes, AS431BNTR-G1 can replace Zener diodes in most shunt-regulator configurations, but requires a three-resistor divider network (two for setting voltage, one for bias current) instead of direct cathode-anode connection. Its REF pin adds flexibility but mandates proper divider design to avoid instability or inaccurate setpoints.

Does AS431BNTR-G1 require external compensation capacitors?

No external compensation capacitor is required. The AS431BNTR-G1 remains stable with load capacitances up to 100 µF across cathode voltages of 5 V, 10 V, and 15 V, as verified in Diodes' DS36599 characterization. Only bypass capacitors (e.g., 100 nF ceramic) near the REF pin are recommended for noise immunity.

What is the maximum power dissipation for AS431BNTR-G1 in SOT23 package?

In SOT23 package, AS431BNTR-G1 has a rated power dissipation of 370 mW at 25°C ambient. Derating is required above 25°C at 4.7 mW/°C, limiting practical continuous dissipation to ~200 mW at 70°C ambient-designers must verify junction temperature stays below 150°C using θ_JA = 220°C/W and actual board layout.