Diodes Incorporated AS431BNTR-E1

Overview

AS431BNTR-E1 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 impedance are critical.

For engineers reviewing the AS431BNTR-E1 datasheet, AS431BNTR-E1 pinout, AS431BNTR-E1 application, or AS431BNTR-E1 equivalent, this device serves as a programmable 2.5V reference core with sharp turn-on, low temperature coefficient (20 ppm/°C typ), and stable regulation under capacitive loads up to 100 µF - key for feedback loop design in isolated DC-DC converters and adapter circuits.

Technical Context

The AS431BNTR-E1 implements a bandgap-based reference amplifier driving an NPN output stage, enabling precise cathode-to-anode voltage control via external resistor dividers. Its internal architecture delivers <4.5 mV reference deviation over –40°C to +125°C and maintains regulation with cathode current from 0.4 mA to 100 mA.

It operates as a two-quadrant shunt element: sinking current when V_K > V_REF × (1 + R1/R2), and entering high-impedance off-state (<1 µA) when V_K drops below threshold. Dynamic impedance remains ≤0.5 Ω across 1–100 mA, supporting fast transient response in PWM feedback paths.

Key Specifications

Pinout & Package

SOT23-3 package: 3-pin surface-mount plastic package with gull-wing leads; compact footprint (2.9 × 1.3 mm), JEDEC standard outline, RoHS-compliant and green molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431BIDBZR and AS431ANTR-G1, the AS431BNTR-E1 offers optimal balance of cost, thermal stability (4.5 mV max drift), and low-power operation (0.7 µA I_REF) - making it ideal for cost-sensitive industrial adapters and consumer chargers where 1% reference accuracy suffices.

Availability

AS431BNTR-E1 is available at Aetrix Electronics and suitable for switching power supplies, battery chargers, and precision voltage reference circuits requiring stable component supply, consistent parametric performance, and long-term lifecycle continuity.

Supply support for AS431BNTR-E1 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 solutions for industrial, computing, and consumer markets.

The AS431 belongs to Diodes' precision reference product line, engineered specifically for high-stability shunt regulation in isolated power supplies, battery management, and instrumentation - emphasizing thermal robustness, low noise, and wide operating temperature range.

FAQ

What is the minimum cathode current required for regulation in AS431BNTR-E1?

The AS431BNTR-E1 requires a minimum cathode current of 0.4 mA to maintain regulation, verified per Electrical Characteristics table (IKA(Min) parameter). This low threshold enables stable operation even with high-value feedback resistors, reducing power consumption in standby modes of AC-DC adapters and IoT power supplies.

Can AS431BNTR-E1 replace TL431 in existing designs without layout changes?

Yes - AS431BNTR-E1 uses the same SOT23-3 package, identical pinout (REF–CATHODE–ANODE), and compatible electrical interface. No PCB redesign is needed; however, reference voltage tolerance differs (1.0% vs. TL431's 0.5% or 1.0% variants), so verify output accuracy margins in final system validation.

Does AS431BNTR-E1 support operation with large output capacitors?

Yes - the AS431BNTR-E1 is characterized for stable operation with ≥100 µF capacitive loads, as confirmed in the Stability Boundary Conditions vs. Load Capacitance plot (Figure 8). No series resistance or compensation network is required, simplifying filter design in high-current charger outputs.

What is the maximum cathode voltage rating for AS431BNTR-E1?

The absolute maximum cathode-to-anode voltage (V_KA) is 40 V, with recommended operating limit of 36 V. Exceeding 36 V risks exceeding power dissipation limits and degrading long-term reliability, especially at elevated ambient temperatures above 85°C.