Vishay BZD27B51P-HE3_A08

Overview

BZD27B51P-HE3_A08 from Vishay Semiconductors is an AEC-Q101-qualified, surface-mount silicon planar Zener diode optimized for overvoltage protection in automotive and industrial power rails. It delivers a nominal Zener voltage of 51 V with ±2 % tolerance at 10 mA test current, 68.2 V clamping voltage at 43 A peak surge current, and operates across -65 °C to +175 °C junction temperature range. It is used in DC-DC converter input protection and ECU power supply transient suppression.

For engineers reviewing the BZD27B51P-HE3_A08 datasheet, BZD27B51P-HE3_A08 pinout, BZD27B51P-HE3_A08 application, or BZD27B51P-HE3_A08 equivalent, key selection criteria include its 150 W 10/1000 μs surge rating, low dynamic resistance (25 Ω), temperature coefficient (+0.07 to +0.12 %/°C), and DO-219AB (SMF) package compatibility with high-density PCB layouts.

Technical Context

This unidirectional Zener diode functions as a precision voltage reference and transient voltage suppressor in parallel configuration. Its design integrates low leakage current (<5 μA at VR = 43 V), stable breakdown behavior under repetitive surges, and MSL level 1 moisture sensitivity for lead-free reflow compatibility.

The device uses a silicon planar junction structure enabling tight Zener voltage control and robust thermal performance, with R_thJA = 180 K/W on 3 mm × 3 mm Cu pads and R_thJL = 30 K/W for efficient heat transfer to the PCB. It meets JESD 201 Class 2 whisker testing and supports wave and reflow soldering up to 260 °C peak.

Key Specifications

Pinout & Package

DO-219AB (SMF) package: 2-terminal surface-mount device with cathode stripe marking; dimensions 2.7 mm × 3.5 mm × 1.08 mm; MSL level 1; RoHS-compliant; AEC-Q101 qualified.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode protection applications.

Compared with SMBJ51A and P6SMB51A, BZD27B51P-HE3_A08 provides superior voltage accuracy, smaller DO-219AB footprint, and automotive-grade reliability-making it optimal for space-constrained, safety-critical 48 V systems where clamping precision and qualification matter.

Availability

BZD27B51P-HE3_A08 is available at Aetrix Electronics and suitable for automotive ECU protection, industrial DC-DC converter input stages, and renewable energy charge controllers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for BZD27B51P-HE3_A08 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

Vishay Semiconductors is a global leader in discrete semiconductors, specializing in high-reliability diodes, MOSFETs, and optoelectronics for automotive, industrial, and computing markets.

The BZD27B Series targets high-stability Zener applications demanding tight voltage tolerance, surge resilience, and AEC-Q101 compliance - designed specifically for next-generation 48 V automotive architectures and ruggedized industrial power systems.

FAQ

What is the Zener voltage tolerance of BZD27B51P-HE3_A08?

The BZD27B51P-HE3_A08 has a Zener voltage tolerance of ±2 %, specified as 49.98 V minimum to 52.02 V maximum at 10 mA test current. This tight tolerance is confirmed in the Vishay BZD27B Series datasheet Rev. 2.1, Table on page 2. The BZD27B51P-HE3_A08 achieves this via silicon planar process control and post-trim screening, making it suitable for precision voltage reference and clamping applications where standard ±5 % Zeners would require excessive design margin.

Is BZD27B51P-HE3_A08 qualified for automotive use?

Yes, BZD27B51P-HE3_A08 is AEC-Q101 qualified, as indicated by the "-HE3" suffix in the ordering code and explicitly stated in the Vishay datasheet features section. It meets stress test requirements including high-temperature operating life, temperature cycling, and mechanical shock. The BZD27B51P-HE3_A08 is rated for junction temperatures up to +175 °C and supports automotive under-hood applications such as engine control modules and body electronics power rails.

What is the maximum clamping voltage of BZD27B51P-HE3_A08 during surge events?

The maximum clamping voltage of BZD27B51P-HE3_A08 is 68.2 V at a peak surge current of 43 A with a 10/1000 μs waveform, per the electrical characteristics table on page 3 of the Vishay datasheet. This value represents the worst-case voltage imposed on the protected circuit during standardized surge testing and is critical for verifying downstream component voltage ratings. The BZD27B51P-HE3_A08 maintains this clamping performance across its full operating temperature range.

Which package does BZD27B51P-HE3_A08 use, and what are its key dimensions?

BZD27B51P-HE3_A08 uses the DO-219AB (SMF) package, a low-profile surface-mount outline measuring 2.7 mm × 3.5 mm × 1.08 mm. Per the package drawing on page 5 of the Vishay datasheet, it features a cathode stripe marking, 0.85 mm lead width, and 1.2 mm terminal length. The BZD27B51P-HE3_A08's SMF package offers 30 % smaller footprint than SMB while maintaining MSL level 1 and reflow compatibility up to 260 °C.

Does BZD27B51P-HE3_A08 have a specified dynamic resistance?

Yes, BZD27B51P-HE3_A08 has a maximum dynamic resistance of 25 Ω at I_ZT = 10 mA, as listed in the electrical characteristics table on page 2 of the Vishay datasheet. This parameter reflects the slope of the Zener breakdown curve and directly impacts voltage regulation stability under varying load currents. The BZD27B51P-HE3_A08's low dynamic resistance ensures minimal voltage deviation during transient current steps, improving protection predictability in fast-switching power systems.