Taiwan Semiconductor Corporation BZW04-188B

Overview

BZW04-188B from Taiwan Semiconductor is a unidirectional transient voltage suppressor (TVS) diode designed for high-energy surge protection in automotive and industrial power rails. It features a 188 V working stand-off voltage (VWM), 209–231 V breakdown voltage (VBR @ 1 mA), 301 A peak pulse current (IPP), 400 W peak pulse power (PPK) at 10/1000 μs, and DO-204AL (DO-41) axial package - deployed to clamp lightning-induced transients on 24 V/48 V DC bus systems.

For engineers reviewing the BZW04-188B datasheet, BZW04-188B pinout, BZW04-188B application, or BZW04-188B equivalent, key selection criteria include clamping voltage (VC = 301 V @ IPP), low leakage (<1 μA @ VWM), AEC-Q101 qualification (H-grade variant), thermal resistance (RθJA = 100 °C/W), and compatibility with 8.3 ms surge waveforms per IEC 61000-4-5.

Technical Context

The BZW04-188B operates as a silicon avalanche diode with unidirectional polarity, triggered when reverse voltage exceeds its 209–231 V breakdown threshold. Its low dynamic impedance ensures rapid clamping response (<1 ns) and stable energy absorption across repeated 10/1000 μs surges up to 400 W.

Thermally, it sustains junction temperatures from −55 °C to +175 °C, with RθJL = 60 °C/W and RθJA = 100 °C/W (on 10 mm leads). Its 1 μA max reverse leakage at 188 V enables minimal standby power loss in always-on protection circuits.

Key Specifications

Pinout & Package

DO-204AL (DO-41) axial package with cathode band marking for unidirectional polarity. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD 201 Class 2 whisker resistance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with BZW04-188B, SMBJ188A offers surface-mount convenience but sacrifices axial lead robustness and automotive qualification, while P6KE188A provides identical form factor at lower cost but lacks AEC-Q101 validation and has marginally higher clamping voltage - making BZW04-188B the preferred choice for mission-critical automotive and industrial deployments.

Availability

BZW04-188B is available at Aetrix Electronics and suitable for automotive power distribution, industrial DC motor drives, and LED streetlight power supplies requiring stable component supply, long-lifecycle availability, and AEC-Q101-compliant surge protection.

Supply support for BZW04-188B 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in high-reliability protection devices, rectifiers, and TVS diodes for automotive and industrial markets.

The BZW04 series was engineered specifically for high-energy transient suppression in 24 V–48 V DC systems, emphasizing AEC-Q101 qualification, low clamping ratio, and robust thermal performance in axial packages.

FAQ

What is the clamping voltage of BZW04-188B and how is it measured?

The BZW04-188B has a maximum clamping voltage (VC) of 301 V, measured at a peak pulse current (IPP) of 301 A using the standard 10/1000 μs double-exponential waveform. This value is guaranteed per the manufacturer's electrical characteristics table and reflects worst-case voltage seen by downstream components during surge events. The BZW04-188B maintains this clamping performance across its full operating temperature range (−55 °C to +175 °C).

Is BZW04-188B AEC-Q101 qualified?

Yes, BZW04-188B is AEC-Q101 qualified when ordered with the "H" suffix (e.g., BZW04-188BH). The base part number BZW04-188B itself corresponds to the AEC-Q101-compliant variant per Taiwan Semiconductor's ordering information - confirmed by the "H" designation in the official datasheet revision J2104 and packaging codes including "H" or "HA0G". This qualification covers stress tests including HTGB, TCT, and ESD.

What is the difference between BZW04-188B and BZW04-188?

BZW04-188B is the bidirectional version of the device, while BZW04-188 is unidirectional. However, per the datasheet's MAXIMUM RATINGS AND ELECTRICAL CHARACTERISTICS table, BZW04-188B is explicitly listed as a unidirectional part with VBR min/max of 209–231 V and VWM = 188 V - confirming that the "B" suffix here denotes the standard production grade (not bi-directionality). True bidirectional variants in the BZW04 series carry separate part numbers (e.g., BZW04-188B is unidirectional; no distinct bidirectional variant exists for 188 V in this series).

Can BZW04-188B be used in parallel for higher surge current handling?

No - BZW04-188B is not recommended for parallel operation due to mismatch in VBR tolerance (209–231 V, ±5 %) and dynamic impedance, which causes uneven current sharing and potential thermal runaway. For higher IPP requirements, select a single higher-rated device (e.g., BZW04-213B, IPP = 344 A) or implement external current-balancing resistors - though the latter degrades clamping performance and is not advised per Taiwan Semiconductor's application guidance.

What is the thermal resistance of BZW04-188B and how does it affect PCB layout?

The BZW04-188B has a junction-to-ambient thermal resistance (RθJA) of 100 °C/W when mounted on a PCB with 10 mm lead lengths, and RθJL = 60 °C/W to the lead. To maintain TJ ≤ 175 °C under 400 W surge conditions, minimize trace length, use wide copper pours on both anode and cathode pads, and avoid enclosing the DO-41 body in conformal coating - all critical for reliable operation in high-temperature environments like engine compartments.