Texas Instruments TLVH431AQLPR

Overview

TLVH431AQLPR from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1% initial tolerance at 25°C (A-grade), and operation down to 1.24 V cathode-anode voltage. It delivers stable regulation across –40°C to +125°C, supports 100 μA to 70 mA cathode current, and features 0.25 Ω typical dynamic impedance-enabling use as a Zener replacement or error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431AQLPR datasheet, TLVH431AQLPR pinout, TLVH431AQLPR application, or TLVH431AQLPR equivalent, key selection criteria include its Q-grade temperature range (–40°C to +125°C), SC-70-6 package footprint, 1.24 V reference accuracy, low minimum cathode current requirement, and compatibility with optocoupler-based secondary-side regulation in 3.3 V power supplies.

Technical Context

The TLVH431AQLPR implements an internal bandgap reference and high-gain transconductance amplifier driving a Darlington output stage. Its functional block includes a precision 1.24 V reference, differential input stage comparing REF to internal VREF, and active sink output at CATHODE-enabling both open-loop comparator and closed-loop shunt regulation modes.

It operates with no external compensation required, achieves sharp turn-on characteristics due to active output circuitry, and maintains stability over 100 μA–70 mA cathode current and 1.24 V–18 V adjustable output voltage range via two external resistors. The Q-grade rating ensures full-spec performance across automotive under-hood and industrial extended-temperature environments.

Key Specifications

Pinout & Package

TLVH431AQLPR is packaged in a 6-pin SC-70 (DCK) package with 2.00 mm × 1.25 mm body size and gull-wing leads. Pin 1 is CATHODE, Pin 2 is ANODE, Pin 3 is REF, Pin 4 and Pin 5 are NC (no internal connection), and Pin 6 is substrate-connected (must be tied to ANODE or left open).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BQLPR, TLVH431AQLPR trades 0.5% reference accuracy for cost efficiency while retaining full Q-grade temperature performance; compared with TLVH432AQLPR, it offers identical functionality but requires PCB layout adaptation due to reversed REF/ANODE/CATHODE pin assignment.

Availability

TLVH431AQLPR is available at Aetrix Electronics and suitable for isolated flyback SMPS regulation, precision voltage monitoring, and low-power comparator applications requiring stable component supply across automotive, industrial, and computing end equipment.

Supply support for TLVH431AQLPR 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 delivering analog and embedded processing solutions, with leadership in precision analog, power management, and signal chain technologies.

The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained and thermally demanding applications-including automotive infotainment power supplies, industrial PLC I/O modules, and telecom DC-DC converters.

FAQ

What is the reference voltage tolerance of TLVH431AQLPR at 25°C?

The TLVH431AQLPR has a reference voltage tolerance of ±1% at 25°C, corresponding to a 1.24 V nominal VREF ranging from 1.228 V to 1.252 V. This A-grade specification is verified per TI's SLVS555N datasheet Section 5.6 and applies across the full Q-grade temperature range when derated per Figure 6-1.

Does TLVH431AQLPR require an output capacitor for stability?

No, TLVH431AQLPR is internally compensated and remains stable without an output capacitor between CATHODE and ANODE under typical operating conditions. Stability data in Figures 5-15 through 5-17 confirm phase margin >45° up to 10 nF capacitive load; external capacitors are optional and used only for specific noise filtering or transient response tuning.

What is the minimum cathode current required for regulation in TLVH431AQLPR?

The TLVH431AQLPR requires a minimum cathode current of 100 μA to maintain regulation, as specified in Section 5.5 of the datasheet. Below this level, gain drops significantly-potentially causing poor line/load regulation or delayed turn-on. Designers must ensure external bias networks deliver ≥100 μA across all operating temperatures and input conditions.

How does the SC-70-6 package of TLVH431AQLPR compare in size to SOT-23-3?

The TLVH431AQLPR SC-70-6 package measures 2.00 mm × 1.25 mm, offering a 40% smaller footprint than the standard SOT-23-3 (2.92 mm × 1.30 mm). This reduction supports high-density PCB layouts in portable and space-constrained applications while maintaining compatible reflow profiles and thermal resistance (R_θJA = 259°C/W).

Can TLVH431AQLPR be used as a comparator, and what are its key advantages in that mode?

Yes, TLVH431AQLPR functions as a comparator in open-loop configuration with integrated 1.24 V reference. Its advantages include ultra-low input bias current (0.1–0.5 μA), fast response (<10 μs), and elimination of external reference components-making it ideal for rail monitoring, battery voltage detection, and logic-level thresholding without additional ICs.