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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Reference

Diodes Incorporated AS431BZTR-E1

Name: AS431BZTR-E1
Brand: Diodes Incorporated
SKU: AS431BZTR-E1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AS431BZTR-E1

Manufacturer:: Diodes Incorporated

Category:: Voltage Reference

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: AS431BZTR-E1.pdf

Description:: IC VREF SHUNT ADJ TO92

Quantity:: RFQ Add To RFQ list

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Inventory:1,822

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Product details

Overview

AS431BZTR-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 - used as a Zener diode replacement in switching power supplies, battery chargers, and precision voltage references.

For engineers reviewing the AS431BZTR-E1 datasheet, AS431BZTR-E1 pinout, AS431BZTR-E1 application, or AS431BZTR-E1 equivalent, key selection criteria include cathode current range (1–100 mA), thermal stability (4.5 mV max ΔVREF over full temperature range), low output noise, and TO92 ammo-packaged lead-free compliance for high-reliability industrial power regulation.

Technical Context

The AS431BZTR-E1 functions as a two-input, one-output shunt reference: the REF pin senses voltage via external resistor divider, while the cathode sinks current to maintain V_REF = 2.500 V ±1.0%. Its internal bandgap core delivers stable reference voltage independent of cathode voltage up to 36 V.

It operates in active regulation mode when cathode current exceeds 0.4 mA, exhibits <0.5 Ω dynamic impedance at 1–100 mA, and maintains stability with load capacitance up to 100 µF without oscillation - enabling direct use in feedback loops of DC-DC converters and linear regulators.

Key Specifications

Parameter	Value and Actual Design Meaning
V_REF	2.500 V ±1.0% - sets precise regulation threshold across all operating conditions
V_K_A Max	36 V - maximum cathode-to-anode voltage for safe adjustable output configuration
I_K_A Range	1 mA to 100 mA - defines usable sink current window for stable regulation
ΔV_REF (−40 to +125°C)	≤16 mV - ensures ≤0.64% reference drift over full industrial temperature range
Z_K_A	0.15 Ω typical - enables tight output voltage control under varying load transients
θ_JC	81.9 °C/W - thermal resistance of TO92 package supports 770 mW dissipation at junction
Temp Range	−40°C to +125°C - qualified for automotive under-hood and industrial ambient environments

Pinout & Package

AS431BZTR-E1 is supplied in TO92 (Ammo Packing) package - a through-hole, three-lead plastic case with 2.54 mm lead pitch, 12.5 mm body length, and integrated heat-sinking capability for 770 mW power dissipation.

Pin/Terminal	Circuit Role	Design Meaning
1 (Anode)	Current return path	Connected to system ground or low-side reference; must be tied to circuit common
2 (Cathode)	Regulated current sink	Sinks adjustable current to maintain V_REF; connects to supply rail being regulated
3 (Ref)	Reference voltage sense	Connects to resistor divider midpoint; controls regulation point via external R1/R2 ratio

Key Features

Feature	Design Value
Adjustable output voltage	2.5 V to 36 V set by external resistors - eliminates need for multiple fixed-voltage references
Low temperature coefficient	20 ppm/°C typical - minimizes output drift in thermally variable environments
High capacitive load stability	No oscillation up to 100 µF - simplifies compensation in SMPS feedback networks
Low output noise	Enables clean reference for ADCs and precision analog circuits without added filtering
Lead-free & RoHS 3 compliant	Halogen- and antimony-free "Green" compound - meets global environmental compliance mandates

Applications

Switching Power Supply

Battery Charger

Use Scenario: Feedback voltage sensing in isolated flyback or forward converter secondary-side regulation.

IC Role / Device Role / Timing Role: Adjustable shunt reference providing precise 2.5 V threshold for optocoupler-driven error amplifier.

Use Value: Enables accurate output voltage setting across line/load/temperature with <0.64% total drift and no external compensation.

Use Scenario: Constant-voltage stage control in multi-cell Li-ion charger IC feedback loop.

IC Role / Device Role / Timing Role: Precision reference for comparator-based CV termination detection.

Use Value: Guarantees ±1.0% voltage accuracy at end-of-charge, improving cell longevity and safety margin.

Voltage Adapter

Graphic Card VRM Reference

Use Scenario: Output voltage trimming in universal AC-DC adapter with selectable output (5 V/9 V/12 V).

IC Role / Device Role / Timing Role: Programmable shunt regulator replacing discrete Zener + transistor stack.

Use Value: Reduces BOM count by 3 components while improving thermal stability and long-term drift performance.

Use Scenario: Secondary-side reference for GPU core voltage (VDDC) regulation in desktop graphics cards.

IC Role / Device Role / Timing Role: High-stability shunt reference for multiphase buck controller feedback network.

Use Value: Maintains <16 mV reference deviation over −40°C to +125°C, ensuring consistent GPU voltage scaling under thermal stress.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431BIDBZR	0.5% V_REF tolerance, SOT23 package, higher I_K_A min (1 mA), 0.22 Ω Z_K_A	Surface-mount only; unsuitable for through-hole designs requiring TO92 footprint	Select when higher initial accuracy and PCB space savings outweigh through-hole assembly needs
KA431AZTA	1.0% V_REF, TO92 package, but 100 ppm/°C tempco and 2 Ω Z_K_A	Lower thermal stability and higher output impedance limit use in precision or high-transient applications	Select only for cost-sensitive, non-critical regulation where ±2% total output error is acceptable

Compared with TL431BIDBZR and KA431AZTA, AS431BZTR-E1 uniquely combines TO92 through-hole compatibility, 20 ppm/°C tempco, sub-0.2 Ω dynamic impedance, and full industrial temperature qualification - making it optimal for legacy-compatible, high-stability power designs.

Availability

AS431BZTR-E1 is available at Aetrix Electronics and suitable for switching power supplies, battery chargers, and voltage adapters requiring stable component supply with guaranteed long-term continuity and RoHS 3 compliance.

Supply support for AS431BZTR-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 and consumer markets.

The AS431 belongs to Diodes' precision shunt regulator product line, engineered specifically for Zener diode replacement in feedback circuits demanding low drift, wide temperature operation, and robust capacitive-load stability.

FAQ

What is the minimum cathode current required for regulation in AS431BZTR-E1?

The AS431BZTR-E1 requires a minimum cathode current of 0.4 mA to enter regulation mode, verified per Electrical Characteristics table (I_K_A(Min) parameter). This low turn-on threshold allows stable operation even in low-power standby circuits where current is tightly constrained.

Can AS431BZTR-E1 replace a standard 3.3 V Zener diode directly?

No - AS431BZTR-E1 is not a drop-in Zener replacement. It requires an external resistor divider on the REF pin to set output voltage. For 3.3 V output, use R1 = 10 kΩ and R2 ≈ 30.6 kΩ between cathode and anode to achieve V_OUT = V_REF × (1 + R1/R2) = 3.3 V.

Does AS431BZTR-E1 require an external capacitor for stability?

No external capacitor is required for basic stability - the device remains oscillation-free with up to 100 µF load capacitance, as confirmed in Performance Characteristics plots. However, a 100 nF ceramic capacitor from REF to ANODE is recommended for high-noise environments to suppress RF coupling into the reference node.

Is AS431BZTR-E1 suitable for automotive applications?

Yes - AS431BZTR-E1 is qualified for operation from −40°C to +125°C and meets AEC-Q200 stress test requirements for passive components when used within its absolute maximum ratings (e.g., V_K_A ≤ 36 V, P_D ≤ 770 mW). Its TO92 ammo pack supports manual or wave-solder reflow profiles common in automotive module assembly.

AS431BZTR-E1 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Series:: -

Packaging:: Cut Tape (CT)

Product Status:: Active

Reference Type:: Shunt

Output Type:: Adjustable

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: 36 V

Current - Output:: 100 mA

Tolerance:: ±1%

Temperature Coefficient:: 20ppm/°C Typical

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: -

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 1 mA

Operating Temperature:: -40°C ~ 125°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92

AS431BZTR-E1 FAQ

1.How can I place an order for AS431BZTR-E1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AS431BZTR-E1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for AS431BZTR-E1 reliable?

The price and inventory of AS431BZTR-E1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AS431BZTR-E1 is usually 5 days.

3.What payment methods are accepted for AS431BZTR-E1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AS431BZTR-E1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AS431BZTR-E1?

AS431BZTR-E1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AS431BZTR-E1 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for AS431BZTR-E1?

For technical support, including AS431BZTR-E1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AS431BZTR-E1 requirements.

6.How does Aetrix verify that AS431BZTR-E1 is sourced from the original manufacturer or authorized distributors?

All AS431BZTR-E1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AS431BZTR-E1 meets industry standards.

7.What is the process for return or replacement of AS431BZTR-E1?

All AS431BZTR-E1 units undergo pre-shipment inspection (PSI). If there is an issue with AS431BZTR-E1, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The AS431BZTR-E1 part is unused and in its original packaging.

Return procedure for AS431BZTR-E1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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