Texas Instruments TLV431CLPRE3

Overview

TLV431CLPRE3 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 TLV431CLPRE3 datasheet, TLV431CLPRE3 pinout, TLV431CLPRE3 application, or TLV431CLPRE3 equivalent, this page delivers verified electrical specs, SC-70 package details, functional mode distinctions (open-loop comparator vs. closed-loop shunt regulator), and real-world design implications for 3.3 V SMPS feedback, low-voltage sensing, and board-level voltage clamping.

Technical Context

The TLV431CLPRE3 implements a bandgap-based reference and NPN Darlington output stage, enabling precise 1.24 V threshold detection and sink-current regulation without external compensation. Its open-loop gain supports fast comparator operation, while closed-loop behavior relies on resistive feedback between cathode and reference pins to set output voltages from 1.24 V to 6 V.

It operates with minimum cathode current of 80 µA (typical) and maintains stable regulation across 0°C to 70°C (C-grade), with 4 mV max VREF drift over that range. The device draws only 0.15–0.5 µA reference terminal current and exhibits ultra-low 0.25 Ω dynamic impedance - critical for tight voltage control in optocoupler-coupled feedback paths.

Key Specifications

Pinout & Package

TLV431CLPRE3 is housed in an ultra-small SC-70 (DCK) package (2.0 mm × 1.5 mm), offering 40% smaller footprint than SOT-23-3. Pin 1 is CATHODE, Pin 3 is ANODE, and Pin 6 is REF - with no internal connection on Pins 4 and 5.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431ACLPRE3, TLV431CLPRE3 trades 0.5% initial accuracy for lower cost and same footprint; compared with TLVH431ILP, it offers 40% smaller area and lower quiescent current but sacrifices voltage headroom and current capability - making TLV431CLPRE3 optimal for space-constrained, low-voltage (<6 V), low-power (<15 mA) regulation.

Availability

TLV431CLPRE3 is available at Aetrix Electronics and suitable for isolated flyback power supplies, voltage supervision circuits, and Zener-replacement designs requiring stable component supply, consistent parametric performance, and long-term manufacturability in commercial-temperature applications.

Supply support for TLV431CLPRE3 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 specializing in analog and embedded processing technologies, with leadership in precision analog ICs, power management, and signal chain solutions.

The TLV431 family was designed specifically for low-voltage shunt regulation and integrated-reference comparator applications - targeting cost-sensitive, space-constrained power and sensing systems operating from 1.24 V to 6 V.

FAQ

What is the reference voltage tolerance of TLV431CLPRE3 at 25°C?

The TLV431CLPRE3 has a reference voltage tolerance of ±1.5% at 25°C, meaning its V_REF falls between 1.222 V and 1.258 V under nominal conditions. This is specified in Section 5.5 of the TI datasheet SLVS139Z and distinguishes it from the TLV431A (±1%) and TLV431B (±0.5%) variants. TLV431CLPRE3 maintains this tolerance across its commercial temperature range (0°C to 70°C).

Can TLV431CLPRE3 replace a standard Zener diode in a 3.3 V regulator circuit?

Yes, TLV431CLPRE3 can directly replace low-voltage Zener diodes (e.g., 3.3 V or 2.4 V types) in shunt regulation applications. Its 1.24 V reference enables adjustable output from 1.24 V to 6 V using two resistors, and its 0.25 Ω dynamic impedance provides superior regulation accuracy versus typical Zener diodes with >10 Ω impedance. TLV431CLPRE3 also offers tighter initial tolerance (±1.5% vs. ±5%) and lower temperature drift - confirmed in TI's Electrical Characteristics tables.

What is the minimum cathode current required for TLV431CLPRE3 to regulate properly?

The TLV431CLPRE3 requires a minimum cathode current (I_K(min)) of 80 µA typical to maintain regulation, as specified in Section 5.5 of the datasheet. This value increases slightly over temperature - up to 100 µA maximum across the full 0°C to 70°C range. Supplying less than this may result in loss of regulation or degraded reference accuracy, especially near the lower end of the output voltage range.

Does TLV431CLPRE3 require an output capacitor for stability?

No, TLV431CLPRE3 is internally compensated and stable without an output capacitor between cathode and anode - a key advantage over many op-amp-based references. However, if an output capacitor is added (e.g., for noise filtering), stability depends on capacitive load; Figure 5-19 in the datasheet shows phase margin vs. load capacitance, confirming stability up to ~1 nF for V_KA = 1.25 V. TLV431CLPRE3's design eliminates mandatory external compensation.

What package type is used for TLV431CLPRE3, and how does it compare to SOT-23-3?

TLV431CLPRE3 uses the SC-70 (DCK) package - a 6-pin surface-mount outline measuring 2.0 mm × 1.5 mm. It is 40% smaller in footprint than the SOT-23-3 variant (DBZ), despite having two unused pins (4 and 5). Pin 1 is CATHODE, Pin 3 is ANODE, and Pin 6 is REF - matching functional pin assignments in DBZ but with different physical layout. This compact size supports high-density PCB designs where board space is constrained.