Texas Instruments TLVH431BILPE3

Overview

TLVH431BILPE3 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 0.5% reference voltage tolerance at 25°C, 1.24 V nominal reference voltage, 100 μA minimum cathode current for regulation, and –40°C to +125°C operating temperature range. It functions as an integrated voltage reference and error amplifier in isolated flyback SMPS feedback loops, replacing Zener diodes in low-leakage, on-board regulation applications.

For engineers reviewing the TLVH431BILPE3 datasheet, TLVH431BILPE3 pinout, TLVH431BILPE3 application, or TLVH431BILPE3 equivalent, key selection criteria include reference accuracy over temperature, dynamic impedance (0.25 Ω), cathode current range (100 μA–70 mA), and compatibility with optocoupler-based secondary-side regulation in 3.3 V switching-mode power supplies.

Technical Context

The TLVH431BILPE3 implements a three-terminal shunt-regulator architecture with an internal 1.24 V bandgap reference and high-gain transconductance amplifier driving a Darlington output stage. Its open-loop operation enables comparator functionality with integrated reference, while closed-loop configuration-using external resistive feedback between cathode and reference pins-enables precise adjustable voltage regulation from 1.24 V to 18 V.

It features ultra-low reference input current (0.1–0.5 μA), low dynamic impedance (0.25 Ω typical), and inherent stability without output capacitance. The device is specified across industrial and automotive temperature ranges and supports stable operation with capacitive loads up to 10 nF when properly compensated per TI application guidance.

Key Specifications

Pinout & Package

TLVH431BILPE3 is packaged in TO-92 (LP) format with 3-pin through-hole configuration, 4.30 mm × 4.30 mm body size, and standard lead spacing compatible with legacy PCB footprints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AILPE3, TLVH431BILPE3 delivers tighter initial accuracy critical for high-resolution data acquisition; compared with TLVH432BILPR, it offers through-hole mounting and legacy footprint compatibility but requires different PCB layout and assembly process.

Availability

TLVH431BILPE3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and medical sensor interfaces requiring stable component supply with guaranteed long-term sourcing.

Supply support for TLVH431BILPE3 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies.

The TLVH431 product line was designed for precision voltage reference and error amplification in isolated and non-isolated power conversion, particularly targeting low-voltage, low-power, and high-accuracy applications across automotive, industrial, and computing markets.

FAQ

What is the reference voltage tolerance of TLVH431BILPE3 at 25°C?

The TLVH431BILPE3 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal reference with a range of 1.234 V to 1.246 V. This B-grade accuracy is confirmed in Section 5.7 of the TI datasheet SLVS555N and applies specifically to the TLVH431BILPE3 variant in TO-92 packaging. The tolerance remains stable across its full operating temperature range of –40°C to +125°C, with total deviation limited to 31 mV.

Can TLVH431BILPE3 replace a standard Zener diode in low-leakage applications?

Yes, TLVH431BILPE3 is explicitly designed as a Zener replacement with significantly lower leakage: its off-state cathode current is only 0.02–0.1 μA at 18 V, versus typical Zener leakage in the 1–10 μA range. Its sharp turn-on characteristic, 0.25 Ω dynamic impedance, and integrated 1.24 V reference eliminate external components and improve regulation accuracy. TLVH431BILPE3 achieves this while maintaining compatibility with existing Zener bias networks when configured in shunt mode.

What is the minimum cathode current required for regulation in TLVH431BILPE3?

The minimum cathode current required for regulation in TLVH431BILPE3 is 100 μA, as specified in Section 5.5 of the TI datasheet under IK(min). This value is guaranteed across the full –40°C to +125°C temperature range. Operating below this threshold may result in insufficient open-loop gain and unstable regulation. The device draws only 0.1–0.5 μA at the REF pin, so external resistor networks must be sized to ensure ≥100 μA flows into the CATHODE terminal under all operating conditions.

Does TLVH431BILPE3 require an output capacitor for stability?

No, TLVH431BILPE3 is internally compensated and stable without an output capacitor between CATHODE and ANODE in most configurations. This is a key design advantage over many linear regulators. However, if an output capacitor is used-for noise filtering or transient response-the device's phase margin must be verified against capacitive load; TI provides guidance in Figures 5-15 to 5-17 showing stable operation up to ~10 nF depending on cathode voltage. TLVH431BILPE3's inherent stability simplifies layout and reduces BOM count.

How does TLVH431BILPE3 function in comparator mode with integrated reference?

In comparator mode, TLVH431BILPE3 compares voltage at the REF pin to its internal 1.24 V reference. When the REF voltage exceeds 1.24 V, the Darlington output sinks cathode current; when below, it cuts off. This open-loop behavior-enabled by supplying ≥100 μA to the CATHODE-provides fast, rail-to-rail switching ideal for undervoltage detection or logic-level translation. Unlike discrete comparators, TLVH431BILPE3 integrates the reference, eliminating external components and reducing board area while maintaining predictable hysteresis-free thresholds.