Texas Instruments TLVH431CLP

Overview

TLVH431CLP from Texas Instruments is a low-voltage adjustable precision shunt regulator in TO-92 package, providing 1.24 V reference voltage with ±1.5% initial tolerance at 25°C, 100 μA to 70 mA cathode current range, and operation from –40°C to +125°C. It functions as an error amplifier or comparator with integrated reference in isolated flyback SMPS feedback loops and on-board voltage monitoring circuits.

For engineers reviewing the TLVH431CLP datasheet, TLVH431CLP pinout, TLVH431CLP application, or TLVH431CLP equivalent, key selection criteria include reference voltage accuracy over temperature, minimum cathode current for regulation (100 μA), dynamic impedance (0.25 Ω), and compatibility with optocoupler-based secondary-side regulation in 3.3 V switching-mode power supplies.

Technical Context

The TLVH431CLP implements a bandgap-referenced error amplifier with Darlington output stage, enabling precise shunt regulation down to 1.24 V - lower than TL431's 2.5 V reference. Its internal architecture supports both open-loop comparator mode (with integrated 1.24 V threshold) and closed-loop shunt regulation via external resistor divider feedback between cathode and reference pins.

It operates without mandatory output capacitance due to internal compensation, but stability under capacitive load is characterized up to 100 nF across cathode–anode. The device maintains 0.25 Ω typical dynamic impedance and exhibits <0.1 μA off-state cathode current at 18 V, supporting low-power rail monitoring and Zener replacement applications.

Key Specifications

Pinout & Package

TLVH431CLP uses a 3-pin TO-92 package (4.30 mm × 4.30 mm body size) with through-hole mounting. Pin 1 is CATHODE, Pin 2 is ANODE, and Pin 3 is REF - matching standard TO-92 orientation per TI's mechanical drawing SLVS555N.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AILP and TLVH431BCLP, the TLVH431CLP offers optimal cost-performance balance for industrial power monitoring and general-purpose SMPS feedback where ±1.5% reference accuracy suffices and board space constraints favor TO-92 through-hole assembly.

Availability

TLVH431CLP is available at Aetrix Electronics and suitable for industrial power monitoring, isolated flyback SMPS feedback, and precision voltage reference applications requiring stable component supply across extended temperature ranges.

Supply support for TLVH431CLP 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 company specializing in analog and embedded processing technologies, with leadership in precision analog ICs and power management solutions.

The TLVH431 family was designed for low-voltage shunt regulation in space-constrained, thermally demanding applications - particularly secondary-side feedback in 3.3 V and 5 V isolated DC/DC converters and high-accuracy voltage monitoring in automotive and industrial control systems.

FAQ

What is the reference voltage tolerance of TLVH431CLP at 25°C?

The TLVH431CLP has a reference voltage tolerance of ±1.5% at 25°C, corresponding to a V_REF range of 1.222 V to 1.258 V. This grade is designated by the absence of suffix 'A' or 'B' in the part number. The device maintains specified performance across –40°C to +125°C, with total V_REF deviation up to 31 mV in the Q-grade temperature range.

Can TLVH431CLP replace a Zener diode in low-leakage applications?

Yes, TLVH431CLP replaces Zener diodes with significantly lower leakage: its off-state cathode current is only 0.02–0.1 μA at 18 V, versus >1 μA for typical 1N4733A (5.1 V) or 1N4742A (12 V) Zeners. Combined with sharp turn-on and 0.25 Ω dynamic impedance, TLVH431CLP delivers superior regulation accuracy and thermal stability in voltage-clamp and rail-monitoring roles.

What is the minimum cathode current required for regulation in TLVH431CLP?

The TLVH431CLP requires a minimum cathode current of 100 μA to maintain regulation, as specified in the electrical characteristics table. Below this level, gain drops and regulation degrades - critical for battery-powered voltage monitors or high-impedance feedback networks. Designers must ensure external bias or load current meets this threshold across all operating conditions.

Does TLVH431CLP require an output capacitor for stability?

No, TLVH431CLP is internally compensated and stable without an output capacitor between cathode and anode. However, if a capacitor is used for noise filtering or transient suppression, TI provides phase-margin vs. capacitive-load curves (Figures 5-15 to 5-17) to guide selection - stability is maintained up to ~100 nF depending on cathode voltage and load conditions.

How does the pinout of TLVH431CLP differ from TLVH432 variants?

TLVH431CLP uses standard TO-92 pinout: Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF. TLVH432 variants reverse REF and ANODE (e.g., SOT-23-3: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE). This difference prevents direct substitution - TLVH431CLP must be used with feedback networks referenced to its specific pin configuration to avoid misregulation or damage.