Taiwan Semiconductor Corporation BZW04-17B

Overview

BZW04-17B from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode designed for primary-level overvoltage protection in DC power rails and signal lines. It features a 17.1V working stand-off voltage (VWM), 19.0–21.0V breakdown voltage (VBR) at 1mA test current, 27.7V maximum clamping voltage (VC) at 14.5A peak pulse current, and operates across –55°C to +175°C junction temperature range - deployed in automotive lighting control modules and industrial sensor interfaces.

For engineers reviewing the BZW04-17B datasheet, BZW04-17B pinout, BZW04-17B application, or BZW04-17B equivalent, key selection criteria include clamping performance under 10/1000μs surge, low leakage (<1μA @ VWM), AEC-Q101 qualification eligibility (H-suffix variant), DO-41 mechanical compatibility, and thermal resistance (R_θJL = 60°C/W) for PCB layout thermal management.

Technical Context

The BZW04-17B is a silicon avalanche diode optimized for fast-response transient suppression in unidirectional configurations. Its 10/1000μs waveform rating delivers 400W peak pulse power with 27.7V clamping at 14.5A, and exhibits <1μA reverse leakage above 17.1V - enabling reliable hold-off in 12–24V systems before clamping onset.

Thermally, it supports operation up to 175°C junction temperature with R_θJL = 60°C/W and R_θJA = 100°C/W (on 10mm lead length PCB), and meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements - confirming suitability for under-hood automotive and industrial environments.

Key Specifications

Pinout & Package

Package: DO-204AL (DO-41), axial-leaded, epoxy-molded case with cathode band marking for unidirectional polarity. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD201 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 BZW04-17B, SMBJ17A offers superior thermal dissipation in SMT layouts but demands PCB redesign, while P6KE17A retains axial form factor and surge rating but trades off leakage performance - making BZW04-17B optimal for new AEC-Q101-eligible 12V/24V designs needing low IR and DO-41 compatibility.

Availability

BZW04-17B is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor interface, and motor drive gate driver protection requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for BZW04-17B 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 power devices and protection components.

The BZW04 series was developed specifically for automotive and industrial transient suppression, emphasizing AEC-Q101 readiness, tight VBR tolerance, and robust DO-41 packaging for harsh-environment deployment.

FAQ

What is the polarity configuration of the BZW04-17B?

The BZW04-17B is a unidirectional TVS diode with marked cathode band indicating the high-side terminal. It conducts avalanche current only when cathode voltage exceeds anode voltage by ≥19.0V - making it suitable for DC rail protection where polarity is fixed. Bidirectional variants (e.g., BZW04-17BB) exist but are distinct part numbers; BZW04-17B must not be used in AC or bipolar signal paths without external rectification.

Does the BZW04-17B meet AEC-Q101 qualification?

The base BZW04-17B is not AEC-Q101 qualified; however, the BZW04-17BH variant - identified by the "H" suffix in the ordering code - is fully AEC-Q101 tested and certified. This distinction is critical for automotive applications: only BZW04-17BH may be used in qualified modules, while BZW04-17B remains appropriate for industrial or consumer-grade designs where qualification is not mandated.

How does the clamping voltage of BZW04-17B compare to its breakdown voltage?

The BZW04-17B has a VBR range of 19.0–21.0V at 1mA and a maximum clamping voltage VC of 27.7V at 14.5A (10/1000μs). This yields a clamping ratio (VC/VBR) of ~1.42, which is typical for high-power DO-41 TVS diodes. The ratio confirms effective energy diversion without excessive overshoot - essential for protecting 3.3V or 5V logic that may sit downstream of the BZW04-17B via local regulation.

Can BZW04-17B be used in parallel for higher surge current handling?

No - BZW04-17B is not recommended for parallel operation due to VBR unit-to-unit variation (±5% typical). Mismatched breakdown voltages cause current imbalance, leading to premature failure of the lower-VBR device. For higher IPP, select a single higher-rated device (e.g., BZW04-20B) or verify matched-bin selection with TSC; parallel use voids reliability guarantees and violates JEDEC derating guidelines.

What is the maximum allowable PCB trace length between BZW04-17B and protected IC?

To maintain sub-10ns response, PCB trace inductance must be minimized: total loop inductance (anode-to-cathode path) should remain below 10 nH. This typically requires trace lengths ≤10 mm with wide, short paths and direct grounding to a solid plane - verified via TDR measurement. Longer traces increase clamping voltage overshoot beyond the rated 27.7V, risking damage to the BZW04-17B itself or downstream components.