Texas Instruments TLVH431AIDCKR

Overview

TLVH431AIDCKR from Texas Instruments is a low-voltage adjustable precision shunt regulator in SC-70-6 package, featuring 1.24 V reference voltage (±1% at 25°C), 100 μA to 70 mA cathode current range, 0.25 Ω typical dynamic impedance, and operation from –40°C to +125°C. It serves as an ultra-low-voltage Zener replacement and error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431AIDCKR datasheet, TLVH431AIDCKR pinout, TLVH431AIDCKR application, or TLVH431AIDCKR equivalent, key selection criteria include reference tolerance grade (A = 1%), SC-70 footprint constraints, cathode current headroom for regulation stability, and compatibility with optocoupler-based secondary-side control in 3.3 V systems.

Technical Context

The TLVH431AIDCKR implements a precision bandgap reference (1.24 V) paired with a high-gain NPN-based error amplifier driving a Darlington sink output stage. Its open-loop comparator mode enables rail-to-rail threshold detection without external reference, while closed-loop operation with resistive feedback achieves stable voltage regulation down to 1.24 V.

Unlike the TL431, it operates with ≥1.24 V cathode-anode differential and supports minimum cathode current as low as 100 μA-enabling efficient regulation in low-power 3.3 V and battery-backed systems. Internal compensation ensures stability without mandatory output capacitance, though phase margin vs. capacitive load is characterized up to 100 nF.

Key Specifications

Pinout & Package

TLVH431AIDCKR uses the SC-70-6 (DCK) package, measuring 2.00 mm × 1.25 mm with 0.65 mm pitch. Pin 2 is substrate-connected and must be tied to ANODE or left floating per TI specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BIDCKR and TLVH432AIDCKR, TLVH431AIDCKR offers optimal balance of cost, accuracy, and layout flexibility for general-purpose 3.3 V flyback regulation and rail monitoring-avoiding over-specification while maintaining robust thermal and dynamic performance across industrial temperature ranges.

Availability

TLVH431AIDCKR is available at Aetrix Electronics and suitable for isolated power supplies, voltage supervision circuits, and precision analog reference designs requiring stable component supply with guaranteed long-term manufacturability.

Supply support for TLVH431AIDCKR 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 with emphasis on reliability, energy efficiency, and system integration.

The TLVH431 family was designed specifically for low-voltage shunt regulation and integrated-reference comparator applications in space-constrained, thermally demanding systems such as automotive body electronics and industrial IoT edge nodes.

FAQ

What is the reference voltage tolerance of TLVH431AIDCKR at 25°C?

The TLVH431AIDCKR has a reference voltage tolerance of ±1% at 25°C, corresponding to a 1.24 V nominal V_REF ranging from 1.228 V to 1.252 V. This A-grade tolerance is specified in Section 5.6 of the TI SLVS555N datasheet and applies across all temperature grades (C/I/Q) of the TLVH431A variant. The TLVH431AIDCKR maintains this accuracy without external trimming.

Can TLVH431AIDCKR replace a standard TL431 in existing designs?

TLVH431AIDCKR cannot directly replace TL431 due to fundamental differences: TL431 requires ≥2.5 V reference and ≥1 mA cathode current, while TLVH431AIDCKR operates down to 1.24 V with only 100 μA minimum cathode current. Substitution requires redesigning feedback resistors, verifying headroom, and confirming SC-70-6 footprint compatibility. It is not a drop-in replacement.

What is the maximum cathode voltage rating for TLVH431AIDCKR?

The absolute maximum cathode voltage (V_KA) for TLVH431AIDCKR is 20 V, defined as voltage at the CATHODE pin relative to the ANODE pin. Continuous operation is rated up to 18 V per Recommended Operating Conditions (Section 5.3). Exceeding 20 V risks permanent damage, and operation above 18 V is outside guaranteed specifications.

Does TLVH431AIDCKR require an output capacitor for stability?

No, TLVH431AIDCKR is internally compensated and stable without an output capacitor between CATHODE and ANODE in standard shunt regulator configurations. However, when driving capacitive loads >100 nF or operating in high-noise environments, TI provides phase margin vs. capacitive load curves (Figures 5-15–5-17) to guide optional capacitor selection for enhanced transient immunity.

How does the SC-70-6 package of TLVH431AIDCKR affect thermal performance?

The SC-70-6 (DCK) package of TLVH431AIDCKR has a junction-to-ambient thermal resistance (R_θJA) of 259°C/W, higher than SOT-23-3 (206°C/W) or SOT-89 (52°C/W). This limits continuous power dissipation in still-air environments; for >150 mW applications, thermal relief pads or airflow must be implemented to avoid exceeding 125°C junction temperature.