Diodes Incorporated ZR431F01TC

Overview

ZR431F01TC from Diodes Incorporated is a three-terminal adjustable precision shunt regulator in SOT23 package, offering 1% reference voltage tolerance (2.475–2.525 V), 72 ppm/°C max temperature coefficient, and 50 µA to 100 mA cathode current sink capability. It replaces standard Zener diodes in voltage monitoring, overvoltage protection, and switch-mode power supply feedback loops where stable 2.5–20 V programmable regulation is required.

For engineers reviewing the ZR431F01TC datasheet, ZR431F01TC pinout, ZR431F01TC application, or ZR431F01TC equivalent, this device supports precise programmable shunt regulation with low dynamic impedance (≤0.75 Ω), sub-µA reference input current, and full-temperature-range stability - critical for high-reliability analog control and power management circuits.

Technical Context

The ZR431F01TC operates as a two-input, one-output precision reference amplifier: its REF pin senses a resistive divider output, while the cathode (VZ) sinks current to maintain VREF at 2.50 V ±1%. Its internal bandgap core is trimmed for tight initial accuracy and compensated across –40°C to +125°C.

It functions in closed-loop shunt mode - regulating output voltage by adjusting cathode current based on REF error - and exhibits <0.1 µA off-state leakage at 20 V cathode voltage. Dynamic impedance remains ≤0.75 Ω at DC and stays below 10 Ω up to 100 kHz, enabling stable operation with capacitive loads up to 1 µF.

Key Specifications

Pinout & Package

SOT23-3 package (JEDEC TO-236AB), 3.0 × 1.4 × 1.1 mm body, matte tin-plated leads, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431BIDBZR and AS431ASTZTR-G1, the ZR431F01TC offers superior temperature coefficient (72 ppm/°C vs. 92/50) and ultra-low IREF (0.12–1.0 µA), making it optimal for high-precision, low-power, wide-temperature applications where divider loading and thermal drift must be minimized.

Availability

ZR431F01TC is available at Aetrix Electronics and suitable for shunt regulators, overvoltage protections, and switch-mode power supplies requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for ZR431F01TC 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-performance, high-reliability components for power management, signal integrity, and protection.

The ZR431 belongs to Diodes' precision reference regulator product line, designed specifically for cost-sensitive, space-constrained applications demanding Zener-level simplicity with IC-grade accuracy, stability, and programmability.

FAQ

What is the minimum cathode current required for regulation in ZR431F01TC?

The ZR431F01TC requires a minimum cathode current (IZ(MIN)) of 35–50 µA to maintain regulation at VREF = 2.50 V. This value is specified at TA = +25°C and applies across the full operating temperature range. Below this threshold, the device exits regulation and VZ drops toward the forward voltage of the internal junction.

Can ZR431F01TC replace TL431 in existing designs without layout changes?

Yes - ZR431F01TC uses the same SOT23-3 package and identical pinout (Cathode–Anode–REF) as TL431 variants, enabling direct drop-in replacement. However, verify that the external resistor divider and load conditions meet ZR431's lower IREF (0.12–1.0 µA vs. TL431's 1–4 µA) and tighter tempco requirements for optimal performance.

What is the maximum stable capacitive load for ZR431F01TC in shunt configuration?

The ZR431F01TC remains stable with capacitive loads up to 1 µF when used in standard shunt regulator configurations, as confirmed by stability boundary testing in the datasheet. For loads >100 nF, ensure the cathode trace has low inductance and consider adding a small series resistor (e.g., 1–10 Ω) if oscillation is observed in high-dV/dt environments.

Is ZR431F01TC qualified for automotive applications?

No - ZR431F01TC is not AEC-Q100 qualified. While it operates from –40°C to +125°C and meets industrial reliability standards, Diodes explicitly states that automotive-grade versions require separate qualification (PPAP, IATF 16949 manufacturing, AEC-Q200 stress testing). Customers needing automotive compliance must contact Diodes for qualified alternatives.