Texas Instruments TLV431BIDBZR

Overview

TLV431BIDBZR from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±0.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation down to 1.24 V cathode-anode voltage - used as an error amplifier or voltage reference in isolated flyback SMPS feedback loops.

For engineers reviewing the TLV431BIDBZR datasheet, TLV431BIDBZR pinout, TLV431BIDBZR application, or TLV431BIDBZR equivalent, this page delivers verified electrical specs, SC-70 package details, functional mode distinctions (open-loop comparator vs closed-loop shunt regulation), and real-world design implications for secondary-side regulation and Zener replacement.

Technical Context

The TLV431BIDBZR implements a bandgap-referenced NPN-based error amplifier with Darlington output stage, enabling precise shunt regulation from 1.24 V to 6 V using two external resistors. Its internal reference is trimmed to 1.24 V ±0.5% at 25°C and exhibits 4 mV max drift over 0°C to 70°C.

It operates in two distinct functional modes: open-loop comparator mode (with integrated 1.24 V reference) requiring ≥55 µA cathode current for full gain, and closed-loop shunt regulator mode where feedback from cathode to reference pin forces regulation - both modes stable without output capacitance due to internal compensation.

Key Specifications

Pinout & Package

TLV431BIDBZR is housed in a 6-pin SC-70 (DCK) package with 2.0 mm × 1.5 mm body size and 0.65 mm lead pitch. Pin 1 is CATHODE, Pin 3 is REFERENCE, Pin 6 is ANODE; Pins 2, 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 TLV431BIDBZR, TLV431BIDBVT offers identical regulation performance in a larger, pin-compatible SOT-23-5 package, while TLVH431IDBVR extends voltage and current capability at the cost of reduced precision (1% initial tolerance) and altered pin configuration - making TLV431BIDBZR optimal for space-constrained 3.3 V/5 V systems demanding ±0.5% accuracy.

Availability

TLV431BIDBZR is available at Aetrix Electronics and suitable for isolated flyback SMPS regulation, programmable current sinks, low-power voltage monitors, and Zener diode replacements requiring stable component supply across industrial, computing, and consumer electronics programs.

Supply support for TLV431BIDBZR 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 power management, signal chain, and high-reliability components.

The TLV431BIDBZR belongs to TI's precision shunt regulator product line, designed specifically for low-voltage, high-accuracy feedback in isolated DC-DC converters and voltage supervision circuits where space, power, and accuracy are critical.

FAQ

What is the reference voltage tolerance of TLV431BIDBZR at 25°C?

The TLV431BIDBZR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal value with a range of 1.234 V to 1.246 V. This tighter tolerance versus TLV431A (±1%) and TLV431 (±1.5%) makes TLV431BIDBZR suitable for applications demanding higher initial accuracy, such as precision power supply trimming or calibrated sensor biasing.

Can TLV431BIDBZR operate with a cathode-anode voltage below 2.5 V?

Yes, TLV431BIDBZR is specifically designed for low-voltage operation and functions reliably with cathode-anode voltage (VKA) as low as 1.24 V - unlike the TL431 family which requires ≥2.5 V. This enables direct use in 1.8 V, 2.5 V, and 3.3 V systems without auxiliary biasing, and is confirmed in the device's Recommended Operating Conditions table for VKA = VREF to 6 V.

What is the minimum cathode current required for regulation in TLV431BIDBZR?

The TLV431BIDBZR requires a minimum cathode current (IK(min)) of 55 µA typical to maintain regulation, with a maximum of 100 µA over the full temperature range (–40°C to 125°C). This ultra-low requirement supports energy-efficient designs such as battery-powered voltage monitors and always-on supervisor circuits where standby current must remain sub-100 µA.

How does TLV431BIDBZR differ from TLV431BIDBVT?

TLV431BIDBZR and TLV431BIDBVT share identical electrical specifications including ±0.5% reference tolerance, 0.25 Ω dynamic impedance, and 55 µA min cathode current. The key difference is packaging: TLV431BIDBZR uses the 6-pin SC-70 (DCK) package (2.0 mm × 1.5 mm), while TLV431BIDBVT uses the 5-pin SOT-23-5 (DBV) package (2.90 mm × 2.80 mm) with a dedicated substrate pin. Layout and footprint are not interchangeable.

Is TLV431BIDBZR stable without an output capacitor?

Yes, TLV431BIDBZR is internally compensated and remains stable without an output capacitor between cathode and anode - a key advantage over many linear regulators. This simplifies flyback feedback design and avoids instability from optocoupler capacitance. Stability boundaries for capacitive loading are documented in Figures 5-18 through 5-21 of the datasheet, confirming robust phase margin across 0–1 nF loads at common operating points.