Texas Instruments TLV431BQDBVTE4

Overview

TLV431BQDBVTE4 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 0.5% initial reference voltage tolerance at 25°C, 1.24 V nominal reference voltage, and operation down to 1.24 V cathode-anode voltage. It delivers 0.25 Ω typical dynamic impedance and supports adjustable output from 1.24 V to 6 V using two external resistors - ideal for secondary-side regulation in isolated 3.3 V flyback SMPSs.

For engineers reviewing the TLV431BQDBVTE4 datasheet, TLV431BQDBVTE4 pinout, TLV431BQDBVTE4 application, or TLV431BQDBVTE4 equivalent, key selection criteria include reference accuracy over temperature (±11 mV from –40°C to 125°C), ultra-low 55 µA minimum cathode current for regulation, SC-70 package footprint, and open-loop comparator functionality with integrated reference.

Technical Context

The TLV431BQDBVTE4 implements a precision bandgap reference and high-gain NPN-based error amplifier in a single die, enabling both closed-loop shunt regulation and open-loop comparator operation. Its internal Darlington sink output drives cathode current based on the difference between the REF pin voltage and the 1.24 V internal reference.

In closed-loop configuration, it regulates output voltage via resistive feedback from cathode to REF; in open-loop mode, it functions as a comparator with built-in 1.24 V threshold, requiring ≥55 µA cathode current for full gain and fast response. Thermal drift is specified at ±11 mV across –40°C to 125°C (Q-grade).

Key Specifications

Pinout & Package

TLV431BQDBVTE4 is packaged in the ultra-small SC-70 (DCK) case measuring 2.0 mm × 1.5 mm - 40% smaller than SOT-23-3 - with 6 pins and a thermal resistance of 87°C/W (junction-to-ambient).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BQDBVTE4, TLV431BIDBVTE4 offers identical accuracy and package but reduced temperature range, while TLVH431BQDBVR extends voltage and current capability at the cost of larger dropout and different pin compatibility - neither is pin-for-pin interchangeable, but both serve adjacent design needs in precision shunt regulation.

Availability

TLV431BQDBVTE4 is available at Aetrix Electronics and suitable for automotive power management, industrial sensor signal conditioning, and isolated DC/DC converter design requiring stable component supply and long-term lifecycle support.

Supply support for TLV431BQDBVTE4 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 personal electronics markets.

The TLV431 family was designed specifically as a low-voltage, low-power replacement for the TL431 in space- and energy-constrained applications - emphasizing precision, small footprint, and extended temperature operation for next-generation power systems.

FAQ

What is the reference voltage tolerance of TLV431BQDBVTE4 at 25°C?

The TLV431BQDBVTE4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a V_REF range of 1.234 V to 1.246 V. This tight tolerance is confirmed in Section 5.7 of the official TI datasheet SLVS139Z and applies specifically to the TLV431B grade. The Q-suffix denotes –40°C to 125°C operation, and the tolerance remains valid across that full range as a maximum deviation of ±11 mV.

Can TLV431BQDBVTE4 operate with a cathode-anode voltage below 2.5 V?

Yes, TLV431BQDBVTE4 is explicitly designed for low-voltage operation starting at V_KA = 1.24 V - the value of its internal reference - and supports regulation down to this minimum. Unlike the TL431 (2.5 V reference), the TLV431BQDBVTE4 enables direct use with 1.8 V and 2.5 V supply rails. Its recommended operating V_KA range is 1.24 V to 6 V per Section 5.3 of the datasheet.

What is the minimum cathode current required for regulation in TLV431BQDBVTE4?

The TLV431BQDBVTE4 requires a minimum cathode current (I_K(min)) of 55 µA to maintain regulation, as specified in Section 5.7 of the datasheet under "Minimum cathode current for regulation" for the TLV431BQ variant. This value is guaranteed across the full –40°C to 125°C temperature range and enables reliable operation in ultra-low-power bias networks where traditional shunt regulators would fail.

Does TLV431BQDBVTE4 require an output capacitor for stability?

No, TLV431BQDBVTE4 is internally compensated and stable without an output capacitor between cathode and anode - a key advantage over many linear regulators. Section 7.3 of the datasheet confirms this, noting that external capacitance is optional and only needed if specific phase-margin targets must be met under heavy capacitive loading. Figure 5-19 provides guidance for selecting C_L when used.

How does the SC-70 package of TLV431BQDBVTE4 compare in size to SOT-23-3?

The SC-70 (DCK) package of TLV431BQDBVTE4 measures 2.0 mm × 1.5 mm, which is 40% smaller in footprint than the standard SOT-23-3 package (2.92 mm × 2.37 mm), as stated in the "Features" section of the datasheet. This reduction supports high-density PCB layouts in compact end equipment such as wearables, smart sensors, and modular power bricks - while maintaining thermal performance via R_θJA = 87°C/W.