Nexperia USA Inc. TL431BIDBZR-QR

Overview

TL431BIDBZR-QR from Nexperia is a B-grade (±0.5 %) adjustable precision shunt regulator in SOT23 package, featuring 2.495 V reference voltage, 1 mA to 100 mA sink current capability, and AEC-Q100 Grade 1 qualification for automotive feedback loops. It operates across –40 °C to +85 °C and delivers 0.2 Ω dynamic cathode-anode impedance for stable voltage regulation in isolated SMPS control circuits.

For engineers reviewing the TL431BIDBZR-QR datasheet, TL431BIDBZR-QR pinout, TL431BIDBZR-QR application, or TL431BIDBZR-QR equivalent, key selection criteria include reference tolerance (0.5 %), thermal drift (≤17 mV over –40 °C to +85 °C), cathode-anode voltage range (2.495 V to 36 V), and SOT23 pin-compatible layout with normal pinning (K-REF-A).

Technical Context

The TL431BIDBZR-QR implements a precision bandgap-based reference amplifier driving an NPN output stage, enabling sharp turn-on and low-output-impedance shunt regulation. Its internal architecture supports programmable output voltages via two external resistors while maintaining stability under varying load and temperature conditions.

It operates as a 3-terminal active shunt element-cathode sinks current when REF voltage exceeds 2.495 V, forcing anode-to-cathode conduction to clamp system voltage. The device exhibits 9 mV typical temperature drift (0 °C to 70 °C) and maintains ≤0.5 Ω dynamic impedance below 1 kHz, critical for noise-sensitive feedback paths.

Key Specifications

Pinout & Package

SOT23 plastic surface-mounted package (3 leads), 1.9 mm × 1.1 mm footprint, 0.45 mm nominal height, standard JEDEC outline per Figure 27.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBZR-Q, TL431BIDBZR-QR offers tighter tolerance and wider temperature range for automotive use; compared with TL431BQDBZR-Q, it shares identical specs but uses different marking and belongs to the IDBZR-Q subfamily with –40 °C to +85 °C rating-making it optimal for cost-constrained automotive modules where full 125 °C junction operation is not required.

Availability

TL431BIDBZR-QR is available at Aetrix Electronics and suitable for automotive onboard chargers, industrial isolated DC-DC converters, and programmable lab power supplies requiring stable component supply with AEC-Q100 traceability and consistent 0.5 % reference accuracy.

Supply support for TL431BIDBZR-QR 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

Nexperia is a global semiconductor expert delivering high-performance logic, discrete, and MOSFET solutions optimized for efficiency, reliability, and manufacturability in high-volume applications.

TL431BIDBZR-QR belongs to the TL431-Q family of AEC-Q100-qualified adjustable shunt regulators designed specifically for automotive and industrial feedback control where precision, stability, and qualification rigor are mandatory.

FAQ

What is the maximum cathode-anode voltage for TL431BIDBZR-QR?

The absolute maximum cathode-anode voltage is 37 V per IEC 60134 limiting values. Recommended operating range is 2.495 V to 36 V. Exceeding 37 V risks permanent damage; operation above 36 V violates recommended conditions and may degrade long-term stability even if within absolute max ratings.

Does TL431BIDBZR-QR require an external capacitor at the REF pin?

Yes-a small capacitor (~100 pF) is recommended at the REF pin to damp high-frequency switching noise injected from the primary side in SMPS feedback applications. This improves noise immunity without affecting regulation accuracy or loop response, as confirmed in Figure 26 application note.

Can TL431BIDBZR-QR be used as a precision voltage comparator?

Yes-it functions as a single-supply comparator with temperature-compensated threshold at 2.495 V, as shown in Figure 22. When REF voltage exceeds 2.495 V, cathode conducts; output state change is sharp due to internal gain, enabling reliable level detection without external hysteresis in non-critical applications.

How does the mirrored vs. normal pinning affect TL431BIDBZR-QR layout?

TL431BIDBZR-QR uses normal pinning (K-REF-A, pins 1–2–3), unlike MFDT-suffixed variants with mirrored pinning (REF-K-A). Using a mirrored footprint would reverse cathode and reference connections, causing failure to regulate or excessive REF current. Always verify pin 1 orientation (marking dot) and match to SOT23 outline Figure 27.