Texas Instruments TLVH431IDBVR

Overview

TLVH431IDBVR from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1% 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 integrated voltage reference and error amplifier in isolated flyback SMPS feedback loops, replacing Zener diodes in low-voltage regulation.

For engineers reviewing the TLVH431IDBVR datasheet, TLVH431IDBVR pinout, TLVH431IDBVR application, or TLVH431IDBVR equivalent, key selection criteria include reference accuracy over temperature, minimum cathode current for regulation, dynamic impedance (0.25 Ω), and compatibility with optocoupler-based secondary-side control in 3.3 V switching-mode power supplies.

Technical Context

The TLVH431IDBVR implements a three-terminal shunt topology with internal 1.24 V bandgap reference and high-gain transconductance amplifier driving a Darlington output stage. Its open-loop configuration serves as a comparator with built-in reference; closed-loop operation enables precise voltage regulation via resistive divider feedback between cathode and reference pins.

It achieves stable regulation without external compensation due to internal frequency compensation, supports cathode voltages from 1.24 V to 18 V, and maintains specified performance across industrial and automotive temperature ranges (–40°C to +125°C) with typical 0.25 Ω dynamic impedance and sub-0.5 μA reference input current.

Key Specifications

Pinout & Package

SOT-23-5 package (2.90 mm × 1.60 mm body), with exposed substrate connection on Pin 2 requiring tie to anode or floating per design requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431ACDBVR, TLVH431IDBVR trades 0.5% accuracy for lower cost in mid-precision applications; versus TLVH432IDBZR, it offers substrate control and higher pin count for enhanced noise immunity and layout flexibility in noisy SMPS environments.

Availability

TLVH431IDBVR is available at Aetrix Electronics and suitable for isolated flyback power supplies, precision ADC references, and industrial voltage monitoring systems requiring stable component supply with guaranteed long-term sourcing.

Supply support for TLVH431IDBVR 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 leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The TLVH431 product line delivers low-voltage, high-accuracy shunt references optimized for secondary-side regulation in isolated DC/DC converters and precision voltage monitoring in harsh-temperature environments.

FAQ

What is the reference voltage tolerance of TLVH431IDBVR at 25°C?

The TLVH431IDBVR has a ±1% reference voltage tolerance at 25°C, corresponding to a 1.24 V nominal value ranging from 1.228 V to 1.252 V. This I-grade specification ensures predictable setpoint accuracy in voltage reference and regulation circuits without requiring post-manufacturing calibration. The TLVH431IDBVR maintains this tolerance across its full operating temperature range of –40°C to +125°C with defined deviation limits.

Can TLVH431IDBVR replace a standard Zener diode in low-voltage applications?

Yes, TLVH431IDBVR directly replaces Zener diodes in applications requiring regulation below 2.5 V, such as 1.8 V or 3.3 V rails. Its 1.24 V reference, adjustable up to 18 V via external resistors, ultra-low 0.1–0.5 μA reference current, and sharp turn-on characteristic provide superior accuracy, lower leakage, and better temperature stability than discrete Zeners. The TLVH431IDBVR also eliminates the need for external op-amps in precision shunt configurations.

What is the minimum cathode current required for regulation with TLVH431IDBVR?

The TLVH431IDBVR requires a minimum cathode current of 100 μA to maintain regulation, as specified in its recommended operating conditions. Below this threshold, the device may exit linear operation, causing reference voltage inaccuracy or instability. This low I_K(min) enables efficient light-load regulation in battery-powered systems and standby modes of SMPS where TL431-family devices would fail to regulate.

How does the substrate pin (Pin 2) on TLVH431IDBVR affect circuit design?

Pin 2 on TLVH431IDBVR is an internal substrate connection that must be tied to the ANODE terminal or left electrically floating-never left unconnected or grounded independently. Improper handling causes shifts in reference voltage and increased temperature drift. In PCB layout, this pin should be routed directly to the ANODE net or omitted from copper pours to prevent parasitic coupling. The TLVH431IDBVR's performance specifications assume correct substrate connection per TI's datasheet guidance.

Is TLVH431IDBVR internally compensated for stability?

Yes, TLVH431IDBVR is fully internally compensated and operates stably without an external cathode-to-anode capacitor. This eliminates a common source of layout sensitivity and improves reliability in space-constrained or high-reliability applications. While optional output capacitance can be added for enhanced ripple rejection, TI's characterization confirms stable closed-loop behavior across its full 100 μA–70 mA cathode current range and 1.24 V–18 V voltage range without external compensation components.