Texas Instruments TLVH432BCDBZT

Overview

TLVH432BCDBZT from Texas Instruments is a precision 3-terminal adjustable shunt voltage reference with 0.5% initial tolerance at 25°C, 1.24V nominal reference voltage, and operation down to 1.24V cathode-anode voltage. It delivers 100μA–70mA cathode current, 0.25Ω typical dynamic impedance, and full-spec performance from –40°C to +125°C. It serves as a low-voltage Zener replacement and error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH432BCDBZT datasheet, TLVH432BCDBZT pinout, TLVH432BCDBZT application, or TLVH432BCDBZT equivalent, key selection criteria include reference voltage accuracy (±0.5% B-grade), ultra-low minimum cathode current (100μA), SOT-23-3 pin compatibility with TLVH431 variants, and stable operation without output capacitance in closed-loop regulation.

Technical Context

The TLVH432BCDBZT implements an internal bandgap reference and high-gain NPN-based error amplifier driving a Darlington sink output stage. Its functional block includes a precision 1.24V reference, comparator input at REF, and current-sinking output at CATHODE referenced to ANODE.

It operates in two distinct modes: open-loop comparator mode (REF vs internal VREF) for voltage monitoring, and closed-loop shunt regulator mode (feedback from CATHODE to REF via resistive divider) for precise output voltage control from 1.24V to 18V. Internal compensation ensures stability without external capacitors.

Key Specifications

Pinout & Package

SOT-23-3 package (2.92 mm × 1.30 mm body size), surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH432BCDBZT, TLVH431BCDBZT demands board rework due to reversed REF/CATHODE pins, while TLVH432BIDBZT trades guaranteed 125°C operation and tighter 0.5% tolerance for lower cost and broader commercial availability - making TLVH432BCDBZT optimal for high-reliability, high-precision, extended-temperature designs.

Availability

TLVH432BCDBZT is available at Aetrix Electronics and suitable for isolated SMPS feedback, precision data converter references, and low-power voltage monitoring requiring stable component supply across automotive, industrial, and telecom end equipment.

Supply support for TLVH432BCDBZT 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 specializing in analog, embedded processing, and power management technologies with over 90 years of innovation in precision analog ICs.

The TLVH432 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained and thermally demanding applications - extending the TL431 architecture to 1.24V operation while maintaining robustness and ease of use.

FAQ

What is the reference voltage tolerance of TLVH432BCDBZT at 25°C?

The TLVH432BCDBZT has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24V nominal VREF ranging from 1.234V to 1.246V. This B-grade precision is confirmed in Section 5.7 of the TI SLVS555N datasheet and applies specifically to the TLVH432BCDBZT variant. The tolerance remains stable across its full operating temperature range of –40°C to +125°C, with total deviation limited to ±11 mV for the Q-grade version.

How does TLVH432BCDBZT differ from TLVH431BCDBZT in pin configuration?

TLVH432BCDBZT uses a SOT-23-3 pinout where Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE. In contrast, TLVH431BCDBZT places Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE - a direct reversal of REF and CATHODE terminals. This makes them electrically identical but not pin-compatible; substituting one for the other without PCB modification will cause circuit failure. The TLVH432BCDBZT pinout is optimized for direct replacement of TL431 in existing layouts adapted for 3-pin packages.

What is the minimum cathode current required for regulation in TLVH432BCDBZT?

The TLVH432BCDBZT requires a minimum cathode current (IK(min)) of 100 μA to maintain regulation, as specified in Sections 5.5–5.7 of the datasheet. This value is guaranteed over the full –40°C to +125°C temperature range. Below this threshold, the device exits regulation and behaves as an open-circuit; design margins should target ≥200 μA to ensure robust startup and light-load stability in battery-powered or standby-mode applications.

Can TLVH432BCDBZT operate without an output capacitor?

Yes, TLVH432BCDBZT is internally compensated and stable without an output capacitor between CATHODE and ANODE in standard shunt regulator configurations. This is explicitly stated in Section 7.3 and validated in Figure 5-15 through Figure 5-17 of the datasheet. However, if a capacitor is added for noise filtering or transient response enhancement, its value must be selected per the phase margin curves to avoid oscillation - especially with capacitive loads >1 nF.

What are the absolute maximum ratings for cathode voltage and current in TLVH432BCDBZT?

The absolute maximum cathode voltage (VKA) for TLVH432BCDBZT is 20 V relative to ANODE, and the absolute maximum cathode current (IK) is 80 mA continuous, per Section 5.1 of the SLVS555N datasheet. Exceeding these limits risks permanent damage. For reliable operation, the recommended cathode voltage range is VREF to 18 V, and the recommended continuous cathode current is 0.1 mA to 70 mA - staying well within absolute limits while ensuring specified performance.