Diodes Incorporated ZR2431F01TA

Overview

ZR2431F01TA 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 ZR2431F01TA datasheet, ZR2431F01TA pinout, ZR2431F01TA application, or ZR2431F01TA equivalent, key selection criteria include its SOT23-3 package footprint, low 0.25 Ω dynamic output impedance at 10 mA, 330 mW power dissipation limit, and stable operation from –40°C to +85°C ambient.

Technical Context

The ZR2431F01TA implements a temperature-compensated bandgap reference core with internal error amplifier and output stage, configured as a two-input (V_REF, cathode), one-output (anode) shunt device. Its reference voltage is trimmed to 1.24 V ±1% at 25°C and maintains ≤8 mV deviation over –40°C to +85°C.

It operates in active regulation only when cathode voltage exceeds V_REF (≥1.24 V) and cathode current stays within 100 µA–25 mA. Dynamic output impedance is 0.25–2 Ω depending on bias and frequency, and it remains stable with ≥100 pF cathode–anode capacitance.

Key Specifications

Pinout & Package

ZR2431F01TA is housed in a surface-mount SOT23-3 package (JEDEC TO-236AB), with pin 1 = Cathode, pin 2 = Anode, pin 3 = Reference (V_REF). The package supports reflow soldering and occupies <1.5 mm² PCB area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBVR and KA431AZTA, ZR2431F01TA offers superior initial accuracy (1% vs 2.5%) and tighter thermal stability (52 ppm/°C), making it optimal for precision feedback in compact 3.3 V/5 V SMPS where board space and regulation error budget are constrained.

Availability

ZR2431F01TA is available at Aetrix Electronics and suitable for switch-mode power supplies, voltage monitors, overvoltage protection circuits, and series regulator control requiring stable component supply and guaranteed long-term sourcing.

Supply support for ZR2431F01TA 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 was a UK-based analog IC design house acquired by Diodes Incorporated in 2008; known for high-performance bipolar and precision analog products.

ZR2431 belongs to Zetex's precision shunt regulator product line, designed specifically for replacing zener diodes in feedback, monitoring, and protection circuits demanding better accuracy, stability, and noise performance.

FAQ

What is the minimum cathode current required for regulation at –40°C?

The ZR2431F01TA requires a minimum cathode current of 100 µA to maintain regulation across the full –40°C to +85°C temperature range, per the Absolute Maximum Ratings table and Electrical Characteristics test conditions. At 25°C, regulation begins at 30 µA, but derating is necessary for low-temperature stability.

Can ZR2431F01TA be used in place of a standard 3.3 V zener diode?

Yes - when configured with R1 = 10.0 kΩ and R2 = 16.2 kΩ, ZR2431F01TA delivers a precise 3.3 V output with ±1% initial accuracy and <±8 mV temperature drift. Unlike zeners, it exhibits lower dynamic impedance (0.25 Ω vs >10 Ω) and negligible voltage shift with current changes.

Does ZR2431F01TA require an external capacitor for stability?

No external capacitor is required for basic DC stability. The device remains stable with ≥100 pF cathode–anode capacitance, which is typically provided by PCB trace capacitance or optional EMI filter caps. Instability may occur only if cathode–anode capacitance falls below 100 pF while driving reactive loads.

What is the maximum cathode voltage rating for ZR2431F01TA?

The absolute maximum cathode voltage is 15 V, as specified in the Absolute Maximum Ratings table. Exceeding this voltage risks permanent damage. For applications requiring higher voltage tolerance (e.g., 24 V rails), alternatives like KA431AZTA (36 V max) should be considered.