Diodes Incorporated ZR2431Z01TA

Overview

ZR2431Z01TA from Zetex Semiconductors (now Diodes Incorporated) is a three-terminal adjustable precision shunt regulator with 1% initial reference voltage tolerance, 52 ppm/°C max temperature coefficient, and 100 µA–25 mA cathode current capability. It functions as a programmable 1.24 V bandgap reference in feedback loops of switch-mode power supplies, enabling accurate 3.3 V or 3 V output regulation via external resistor dividers.

For engineers reviewing the ZR2431Z01TA datasheet, ZR2431Z01TA pinout, ZR2431Z01TA application, or ZR2431Z01TA equivalent, key selection criteria include its 1% Vref tolerance, low 0.25–2 Ω dynamic output impedance, 1.24 V reference stability over −40°C to +85°C, and SOT89-3 package thermal performance for medium-power shunt regulation.

Technical Context

The ZR2431Z01TA implements a temperature-compensated bandgap reference core with internal error amplifier and output stage, delivering stable 1.24 V reference voltage across full industrial temperature range. Its cathode-anode architecture supports programmable output voltages from 1.24 V to 15 V using two external resistors, with minimal deviation (<8 mV) over temperature.

Dynamic output impedance is specified at 0.25–2 Ω (measured at 10 mA, DC), and the device maintains regulation down to 30–100 µA minimum cathode current. Off-state leakage remains ≤30 µA at 15 V cathode voltage, supporting low-power monitoring applications.

Key Specifications

Pinout & Package

SOT89-3 package: compact surface-mount thermally enhanced outline with exposed drain pad (pin 2), standard pin 1 = cathode, pin 2 = anode, pin 3 = reference (V_REF). Pin 2 is electrically connected to the die substrate and must be tied to system ground or heat sink for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBVR and KA431AZTA, ZR2431Z01TA delivers tighter 1% Vref tolerance and lower 52 ppm/°C tempco-critical for high-accuracy SMPS feedback-while its SOT89 package supports 1.5 W dissipation, enabling reliable 25 mA operation without heatsinking.

Availability

ZR2431Z01TA is available at Aetrix Electronics and suitable for switch-mode power supplies, voltage monitoring circuits, overvoltage protection systems, and series regulator control requiring stable component supply with guaranteed long-term sourcing.

Supply support for ZR2431Z01TA 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

Zetex Semiconductors, acquired by Diodes Incorporated in 2008, specialized in high-performance analog and power management ICs for industrial and computing applications.

ZR2431 belongs to the precision shunt regulator product line, designed specifically for high-accuracy voltage reference and feedback control in switching power converters and protection circuits.

FAQ

What is the minimum cathode current required for regulation in ZR2431Z01TA?

The ZR2431Z01TA requires a minimum cathode current of 30 µA to maintain regulation under typical conditions, rising to 100 µA at temperature extremes. This value is confirmed in the Absolute Maximum Ratings table and Electrical Characteristics section of the official datasheet, measured at full −40°C to +85°C operating range with 10 mA load current.

Can ZR2431Z01TA replace a standard 3.3 V zener diode directly?

No direct replacement is possible without external resistors. ZR2431Z01TA provides a fixed 1.24 V reference and requires two external resistors to program output voltage (e.g., 3.3 V). Unlike a zener, it cannot be connected anode-to-cathode across a rail-it must be used in active feedback configuration with proper biasing and current sinking.

What is the thermal resistance (θ_JA) of the SOT89-3 package for ZR2431Z01TA?

The SOT89-3 package has a typical junction-to-ambient thermal resistance of 83°C/W when mounted on a 1-inch² 1-oz copper pad, derived from its 1.5 W maximum power dissipation rating at 25°C ambient and 150°C max junction temperature. This value is validated in the Power Dissipation Derating curve on page 4-156 of the datasheet.

Does ZR2431Z01TA require an output capacitor for stability?

Stability depends on circuit configuration: no capacitor is needed for basic shunt regulation, but ≥100 pF between cathode and anode is required if minimum cathode current falls below 0.2 mA. The Stability Boundary Conditions chart (page 4-156) shows stable operation up to 10 µF load capacitance with appropriate series resistance in feedback paths.