Taiwan Semiconductor Corporation 1SMB5950H

Overview

1SMB5950H from Taiwan Semiconductor is a surface-mount silicon Zener diode rated for 3 W power dissipation, with a nominal Zener voltage of 110 V (±5%), test current of 3.4 mA, and maximum DC Zener current of 13 mA. It operates across –55°C to +150°C junction temperature and is used in precision voltage reference and overvoltage protection circuits in automotive and industrial power supplies.

For engineers reviewing the 1SMB5950H datasheet, 1SMB5950H pinout, 1SMB5950H application, or 1SMB5950H equivalent, key selection criteria include its DO-214AA (SMB) package, AEC-Q101 qualification, low inductance, glass-passivated junction, and 4000 Ω dynamic impedance at 300 μA - critical for stable regulation under low-current bias conditions.

Technical Context

The 1SMB5950H functions as a single-die, unidirectional Zener diode optimized for voltage regulation and clamping in DC power rails. Its 110 V nominal breakdown voltage is specified at 3.4 mA test current, with a 0.25 V maximum leakage current at 83.6 V reverse bias and a 25 °C/W junction-to-lead thermal resistance enabling reliable heat transfer in compact PCB layouts.

Designed for automotive-grade reliability, it meets AEC-Q101 stress testing requirements and features matte tin-plated leads compliant with J-STD-002 solderability standards. Its DO-214AA (SMB) package supports automated placement and provides UL 94V-0 flammability-rated molding compound with polarity indicated by cathode band.

Key Specifications

Pinout & Package

DO-214AA (SMB) package: molded plastic case with two axial leads, cathode identified by a visible band; designed for reflow soldering on standard SMT lines with moisture sensitivity level 1 per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMF110A and 1N5375B, the 1SMB5950H uniquely combines AEC-Q101 qualification, 3 W SMT power handling, and tight ±5% voltage tolerance in DO-214AA - making it optimal for space-constrained, high-reliability automotive and industrial voltage reference designs.

Availability

1SMB5950H is available at Aetrix Electronics and suitable for automotive power supply regulation, industrial sensor reference voltage generation, and DC link overvoltage protection requiring stable component supply across production lifecycles.

Supply support for 1SMB5950H 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 semiconductor manufacturer specializing in discrete power devices, including Zener, Schottky, and TVS diodes, with global distribution and AEC-Q101-compliant product lines.

The 1SMB59xxH series was developed specifically for high-voltage, high-reliability Zener regulation in automotive and industrial applications - emphasizing thermal robustness, low-inductance packaging, and tight parametric tolerances.

FAQ

What is the Zener voltage tolerance for 1SMB5950H?

The 1SMB5950H has a nominal Zener voltage of 110 V with a tolerance of ±5%, meaning the actual measured V_Z falls between 104.5 V and 115.5 V at I_ZT = 3.4 mA. This tolerance is confirmed in the Electrical Specifications table on page 2 of the official Taiwan Semiconductor datasheet (Version A2102). The 1SMB5950H achieves this precision via laser trimming during manufacturing and maintains stability under thermal cycling due to its glass-passivated junction.

Is 1SMB5950H qualified for automotive applications?

Yes, the 1SMB5950H is AEC-Q101 qualified, as explicitly stated in the FEATURES section of the Taiwan Semiconductor datasheet. This qualification covers stress tests including temperature cycling, high-temperature operating life, and unbiased highly accelerated stress testing - confirming suitability for under-hood and powertrain electronics. The 1SMB5950H's DO-214AA package and matte tin plating further support automotive assembly requirements per J-STD-002.

What is the maximum DC Zener current for 1SMB5950H?

The maximum DC Zener current (I_ZM) for 1SMB5950H is 13 mA, as listed in the Electrical Specifications table. This value corresponds to the current at which the device reaches its full 3 W power dissipation limit at V_Z = 110 V. Exceeding 13 mA risks thermal runaway unless board-level thermal management (e.g., 5 mm × 5 mm Cu pad) is implemented - a condition verified in the Absolute Maximum Ratings section.

Does 1SMB5950H have a specified Zener impedance at low current?

Yes, the 1SMB5950H specifies Zener impedance (Z_ZK) of 4000 Ω at I_ZK = 300 μA, per the Electrical Specifications table. This low-current impedance is critical for applications where the diode operates near knee voltage, such as precision reference dividers. The 1SMB5950H's 4000 Ω value reflects its design for stable regulation even below nominal test current, supported by its glass-passivated junction and low-inductance SMB package.

What is the thermal resistance from junction to ambient for 1SMB5950H?

The junction-to-ambient thermal resistance (R_θJA) for 1SMB5950H is 226 °C/W, as given in the Thermal Performance table. This value assumes standard JEDEC test conditions (single device on FR-4 board with no copper pour). In practice, the 1SMB5950H achieves significantly better thermal performance - down to 25 °C/W junction-to-lead (R_θJL) - when mounted on a 5 mm × 5 mm copper pad, enabling full 3 W operation without exceeding 150°C junction temperature.