Texas Instruments TL432CDBZT

Overview

TL432CDBZT from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B grade), 6 mV max full-range temperature drift, 0.2 Ω typical dynamic impedance, and 1–100 mA sink-current capability. It serves as an adjustable voltage reference in secondary-side regulation of isolated flyback converters.

For engineers reviewing the TL432CDBZT datasheet, TL432CDBZT pinout, TL432CDBZT application, or TL432CDBZT equivalent, key selection factors include its C-grade (0°C to 70°C) thermal specification, DBZ package pinout distinction from TL431, low reference input current (2–4 µA), and sharp turn-on characteristic enabling Zener diode replacement in space-constrained power supplies.

Technical Context

The TL432CDBZT implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference, and output transistor. Its REF pin senses voltage relative to ANODE, triggering cathode current conduction when the divider voltage exceeds Vref - enabling precise feedback control without external op-amps.

Unlike the TL431, the TL432 variant uses a reversed pinout in DBZ packaging: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. This configuration supports direct integration into compact feedback networks where cathode connects to transformer bias winding and REF ties to optocoupler input.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.90 mm × 1.30 mm body, surface-mount, gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431CDBZR, TL432CDBZT avoids layout rework in DBZ-based designs; compared with TL432LIBDZT, it trades 2 mV higher drift and 2.5 µA higher Iref for cost-sensitive commercial applications where ±0.5% initial tolerance suffices.

Availability

TL432CDBZT is available at Aetrix Electronics and suitable for secondary-side regulation, voltage monitoring, and Zener replacement applications requiring stable component supply across commercial temperature ranges.

Supply support for TL432CDBZT 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 power management and precision analog ICs.

The TL43x family was designed for high-accuracy, low-cost voltage referencing in power supply feedback loops, industrial controls, and safety-critical monitoring - emphasizing thermal stability, low drift, and robust shunt regulation.

FAQ

What is the reference voltage tolerance of TL432CDBZT at 25°C?

The TL432CDBZT has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to the B grade specification. This yields a Vref range of 2.483 V to 2.507 V under nominal conditions, as confirmed in Section 7.11 of the SLVS543P datasheet for TL432BC devices in C-grade temperature range.

How does the TL432CDBZT pinout differ from TL431 in SOT-23-3 packages?

The TL432CDBZT uses a reversed pinout versus TL431CDBZR in SOT-23-3: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. In contrast, TL431CDBZR assigns Pin 1 = REF, Pin 2 = ANODE, Pin 3 = CATHODE. This difference is explicitly documented in the "Pin Configuration and Functions" section of the TL431/TL432 datasheet.

What is the maximum cathode voltage rating for TL432CDBZT?

The TL432CDBZT supports a maximum cathode-to-anode voltage (VKA) of 36 V, as specified in the Absolute Maximum Ratings table (Section 7.1). Exceeding this value risks permanent device damage, and operation above 36 V requires external clamping or derating per TI's reliability guidelines.

Can TL432CDBZT replace a Zener diode in a 5 V regulator circuit?

Yes - the TL432CDBZT can directly replace a 5 V Zener diode using R1 = 10 kΩ and R2 = 10 kΩ to set Vout = Vref × (1 + R1/R2) = 5.0 V. Its 0.2 Ω dynamic impedance and sharp turn-on provide superior regulation accuracy and transient response compared to standard 5% tolerance Zeners.

What is the operating temperature range for TL432CDBZT?

The TL432CDBZT is rated for operation from 0°C to 70°C (C grade), as indicated by the "C" suffix in the part number and confirmed in Section 7.4 (Recommended Operating Conditions). It is not qualified for extended industrial (–40°C to 85°C) or automotive (–40°C to 125°C) temperature ranges.