Diodes Incorporated 1SMB5956B-13

Overview

1SMB5956B-13 from Diodes Incorporated is a 3.0W surface-mount power Zener diode with nominal zener voltage of 200V (±5% tolerance), maximum zener impedance of 8000Ω at 1.9mA test current, and ESD rating >16kV (HBM). It operates from –65°C to +150°C and is used for overvoltage protection and voltage regulation in DC power rails of industrial power supplies.

For engineers reviewing the 1SMB5956B-13 datasheet, 1SMB5956B-13 pinout, 1SMB5956B-13 application, or 1SMB5956B-13 equivalent, key selection criteria include zener voltage accuracy, thermal resistance (226°C/W), peak pulse power capability, reverse leakage at rated VR, and SMB package compatibility with automated SMT assembly.

Technical Context

This discrete Zener diode functions as a precision shunt voltage regulator and transient voltage clamp. Its 200V nominal breakdown voltage is stabilized by a heavily doped PN junction optimized for low dynamic impedance (8000Ω) at low test current (1.9mA) and low temperature coefficient (≈–0.075%/°C per Figure 2).

Designed for high-reliability DC rail protection, it delivers 3.0W continuous power dissipation at TL = +75°C with derating to 550mW at TA = +25°C. The SMB package enables compact layout while supporting FR-4 PCB mounting per AP02001 pad guidelines and meets J-STD-020 Level 1 moisture sensitivity.

Key Specifications

Pinout & Package

Package: SMB (Surface Mount Body), molded plastic case with UL 94V-0 flammability rating, cathode band polarity marking, and matte tin-plated copper alloy leadframe. Dimensions: 3.30–3.94mm (L) × 4.06–4.57mm (W) × 1.96–2.21mm (H).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5388B and SMBJ200A, the 1SMB5956B-13 uniquely balances SMT compatibility, ±5% DC regulation accuracy, and 3.0W steady-state dissipation-making it optimal for space-constrained, thermally managed 200V shunt applications where both precision and reliability are required.

Availability

1SMB5956B-13 is available at Aetrix Electronics and suitable for industrial power supply protection, telecom DC-DC converter clamping, and automotive battery monitoring circuits requiring stable component supply and RoHS-compliant sourcing.

Supply support for 1SMB5956B-13 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The SMB Zener series-including 1SMB5956B-13-is engineered for high-reliability voltage regulation and overvoltage protection in industrial, telecom, and automotive power systems where precision, thermal robustness, and SMT manufacturability are critical.

FAQ

What is the maximum reverse voltage (V_R) at which leakage current is specified for 1SMB5956B-13?

The datasheet specifies maximum reverse leakage current (I_R) of 0.25µA at V_R = 152V - which equals 76% of the nominal 200V zener voltage. This value is measured at T_A = +25°C and defines the upper limit of usable reverse bias before significant conduction begins.

Can 1SMB5956B-13 be used in place of a 1N5388B in a 200V regulator circuit?

No - although both have 200V nominal zener voltage, the 1SMB5956B-13 has 3.0W power rating in SMB package with 226°C/W thermal resistance, whereas the 1N5388B is rated for 5W in DO-201AD with 35°C/W. Substitution would cause thermal runaway under identical load conditions due to insufficient heat dissipation.

What is the typical temperature coefficient of V_Z for 1SMB5956B-13?

Per Figure 2 of DS32125 Rev. 8-2, the temperature coefficient for 200V Zeners in this series is approximately –0.075%/°C - meaning V_Z decreases by ~0.15V over a 100°C rise from +25°C. This negative TC is inherent to high-voltage Zener operation and must be accounted for in precision reference designs.

Is the 1SMB5956B-13 suitable for use in life support equipment?

No - Diodes Incorporated explicitly prohibits use of this device in life support systems without written CEO approval. Its qualification excludes medical safety standards such as ISO 13485 or IEC 62304, and no failure mode analysis or ASIL-rated testing is performed for this part.