Texas Instruments TLVH431BQLPRE3

Overview

TLVH431BQLPRE3 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, and operation down to 1.24 V cathode-to-anode voltage. It delivers 100 μA to 70 mA cathode current, 0.25 Ω typical dynamic impedance, and full-spec operation from –40°C to +125°C. It serves as a Zener replacement and error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431BQLPRE3 datasheet, TLVH431BQLPRE3 pinout, TLVH431BQLPRE3 application, or TLVH431BQLPRE3 equivalent, key selection criteria include reference accuracy grade (B), thermal stability over industrial/automotive temperature ranges, cathode current headroom for optocoupler drive, and SC-70 package footprint compatibility in space-constrained power rails.

Technical Context

The TLVH431BQLPRE3 implements an internal 1.24 V bandgap reference and high-gain NPN-based error amplifier driving a Darlington sink output stage. Its open-loop comparator mode enables precise voltage monitoring without external references, while closed-loop configuration with resistive feedback achieves stable shunt regulation from 1.24 V to 18 V.

Unlike the TL431, it operates with ≥100 μA minimum cathode current and supports lower input voltages-critical for 3.3 V and 2.5 V system rails. The device is internally compensated and stable without output capacitance, though phase margin vs. capacitive load is characterized up to 100 nF for design assurance.

Key Specifications

Pinout & Package

TLVH431BQLPRE3 is packaged in SC-70 (DCK) - a 6-pin surface-mount package measuring 2.00 mm × 1.25 mm with 0.65 mm pitch. Pin 2 connects to substrate and must be tied to ANODE or left open; pins 4 and 5 are NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BQLPRE3, TLVH431BQDBVR offers better thermal resistance but larger area, while TLVH432BQPK provides superior power dissipation in a 3-pin form factor - both retain identical 0.5% reference accuracy and 1.24 V baseline, enabling functional substitution with layout or thermal trade-offs.

Availability

TLVH431BQLPRE3 is available at Aetrix Electronics and suitable for isolated flyback SMPSs, precision data converter references, and automotive voltage monitoring systems requiring stable component supply across extended temperature ranges.

Supply support for TLVH431BQLPRE3 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 for industrial, automotive, and communications markets.

The TLVH431 family was designed specifically for low-voltage shunt regulation and error amplification in isolated power supplies, replacing Zener diodes and discrete op-amp/reference combinations with integrated, temperature-stable performance.

FAQ

What is the reference voltage tolerance of TLVH431BQLPRE3 at 25°C?

The TLVH431BQLPRE3 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal value ranging from 1.234 V to 1.246 V. This B-grade accuracy is confirmed in Section 5.7 of the TI SLVS555N datasheet and applies across all operating conditions unless otherwise specified. TLVH431BQLPRE3 maintains this tolerance specification under its full rated cathode current range and thermal profile.

Can TLVH431BQLPRE3 operate with cathode voltage below 2.5 V?

Yes, TLVH431BQLPRE3 operates down to 1.24 V cathode-to-anode voltage - significantly lower than the 2.5 V minimum of the TL431. This capability is explicitly stated in the "Features" section and validated across its full –40°C to +125°C temperature range. TLVH431BQLPRE3 achieves regulation at 1.24 V with ≥100 μA cathode current, making it suitable for 1.8 V, 2.5 V, and 3.3 V system rails.

What is the maximum cathode current rating for TLVH431BQLPRE3?

The absolute maximum cathode current for TLVH431BQLPRE3 is 80 mA, per Section 5.1 Absolute Maximum Ratings. However, the recommended continuous operating range is 100 μA to 70 mA, as defined in Section 5.3 Recommended Operating Conditions. Exceeding 70 mA may compromise thermal performance in the SC-70 package due to its 259°C/W junction-to-ambient thermal resistance.

Does TLVH431BQLPRE3 require an output capacitor for stability?

No, TLVH431BQLPRE3 is internally compensated and stable without an output capacitor between cathode and anode. This is confirmed in Section 7.3 Feature Description. While optional capacitors up to 100 nF can be used for noise filtering, Figure 5-15 through 5-17 show that stability is maintained across load capacitance - eliminating mandatory external compensation and reducing design risk in compact layouts.

How does the SC-70 package of TLVH431BQLPRE3 compare to SOT-23 variants?

The TLVH431BQLPRE3 SC-70 (DCK) package measures 2.00 mm × 1.25 mm - 40% smaller than the SOT-23-3 (DBZ) variant - and features six pins with dedicated NC and substrate connections. Its RθJA is 259°C/W, higher than SOT-23-5 (206°C/W) or SOT-89 (52°C/W), so thermal derating is required above 30 mA continuous cathode current. TLVH431BQLPRE3 retains identical electrical specs, making it ideal for space-constrained but thermally moderate applications.