Texas Instruments TLV431CLPE3

Overview

TLV431CLPE3 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation down to 1.24 V cathode-anode voltage - used as an integrated reference in isolated flyback secondary-side regulation, Zener replacement, and voltage monitoring circuits.

For engineers reviewing the TLV431CLPE3 datasheet, TLV431CLPE3 pinout, TLV431CLPE3 application, or TLV431CLPE3 equivalent, key selection considerations include its 1.24 V reference accuracy over temperature, ultra-low 80 µA minimum cathode current, SC-70 (DCK) package footprint, and compatibility with optocoupler-based feedback in 3.3 V SMPS designs.

Technical Context

The TLV431CLPE3 implements a bandgap-referenced error amplifier driving a Darlington sink output stage, enabling precise shunt regulation via external resistor feedback between cathode and reference pins. Its internal architecture supports both open-loop comparator mode (with integrated 1.24 V threshold) and closed-loop shunt regulation mode without requiring external compensation.

It operates across 0°C to 70°C (C-grade), delivers stable regulation with cathode currents from 80 µA to 15 mA, and maintains <12 mV reference deviation over full temperature range - making it suitable for low-headroom, low-power voltage referencing where TL431-class devices cannot operate.

Key Specifications

Pinout & Package

TLV431CLPE3 is housed in a 6-pin SC-70 (DCK) package with exposed substrate pad. Pin 2 is substrate-connected and must be tied to anode or left floating; all other pins are electrically active per functional mapping below.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431ACLP, TLV431CLPE3 trades 0.5% initial accuracy for lower cost and sufficient stability in cost-sensitive commercial power supplies; compared with TLVH431ILP, it offers smaller size and lower quiescent current but limits maximum cathode voltage to 6 V.

Availability

TLV431CLPE3 is available at Aetrix Electronics and suitable for isolated SMPS feedback, voltage supervision, and Zener replacement applications requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for TLV431CLPE3 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 TLV431 family was designed specifically for low-voltage, low-power shunt regulation and integrated reference applications - targeting space- and energy-constrained systems such as isolated DC/DC converters, battery monitors, and portable electronics.

FAQ

What is the reference voltage tolerance of TLV431CLPE3 at 25°C?

The TLV431CLPE3 has a reference voltage tolerance of ±1.5% at 25°C, corresponding to a 1.24 V nominal reference with a range of 1.222 V to 1.258 V. This grade is designated by the absence of 'A' or 'B' suffix - 'C' indicates commercial temperature range (0°C to 70°C), and no letter after 'TLV431' specifies the 1.5% initial accuracy bin.

Can TLV431CLPE3 replace a standard Zener diode in a 3.3 V regulation circuit?

Yes, TLV431CLPE3 can directly replace a 3.3 V Zener diode using two external resistors to set the output voltage to 3.3 V. Its 0.25 Ω dynamic impedance, ±1.5% initial tolerance, and sharp turn-on characteristic provide significantly better regulation accuracy, thermal stability, and load transient response than discrete Zeners.

What is the minimum cathode current required for regulation in TLV431CLPE3?

The TLV431CLPE3 requires a minimum cathode current of 80 µA typical (up to 100 µA over temperature) to maintain regulation. This ultra-low requirement enables operation in micropower systems where traditional TL431 (1 mA min) would fail - critical for battery-backed or energy-harvesting applications.

Which package does TLV431CLPE3 use, and how does it differ from SOT-23-3?

TLV431CLPE3 uses the SC-70 (DCK) package - a 6-pin surface-mount outline measuring 2.0 mm × 1.5 mm. It is 40% smaller than SOT-23-3 and includes dedicated NC pins and a substrate terminal (Pin 2), unlike the 3-pin SOT-23 which integrates anode, cathode, and reference in a single compact body.

Does TLV431CLPE3 require an external compensation capacitor for stability?

No, TLV431CLPE3 is internally compensated and remains stable without an external output capacitor between cathode and anode. This eliminates layout sensitivity and capacitor-selection uncertainty common in shunt regulator designs - though optional capacitors can be added if phase margin analysis (per Figure 5-19) indicates benefit for specific load conditions.