Diodes Incorporated 1SMB5954B-13

Overview

1SMB5954B-13 from Diodes Incorporated is a 3.0W surface-mount power Zener diode with nominal zener voltage of 160 V (min 152 V, max 168 V), ±5% tolerance, 2.3 mA test current, and 700 Ω dynamic impedance at I_ZT. It provides precise voltage regulation in overvoltage protection circuits for industrial power supplies and DC bus clamping.

For engineers reviewing the 1SMB5954B-13 datasheet, 1SMB5954B-13 pinout, 1SMB5954B-13 application, or 1SMB5954B-13 equivalent, key selection criteria include zener voltage accuracy, thermal resistance (R_θJA = 226 °C/W), ESD robustness (>16 kV HBM), and SMB package compatibility with automated SMT assembly.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable reference voltage under varying load and temperature conditions. Its 160 V nominal zener voltage targets high-voltage rail stabilization in telecom power converters and motor drive snubbers.

The device features low leakage (<0.25 µA at 121.6 V), high surge capability (peak pulse power up to 1.5 kW for 10 ms), and a temperature coefficient of +0.115 %/°C - confirmed by Figure 2 in DS32125 Rev. 8-2 - enabling predictable drift compensation in precision clamping designs.

Key Specifications

Pinout & Package

Package: SMB (Surface Mount Body), molded plastic case per UL 94V-0, polarity indicated by cathode band. Dimensions: 3.30–3.94 mm (L) × 4.06–4.57 mm (W) × 1.96–2.21 mm (H). Weight: 0.096 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ160A and 1N5954B, the 1SMB5954B-13 uniquely combines 3.0 W continuous dissipation, SMB SMT footprint, and tight ±5% V_Z tolerance - making it the only option qualified for both steady-state regulation and repetitive surge clamping in space-constrained industrial power modules.

Availability

1SMB5954B-13 is available at Aetrix Electronics and suitable for industrial power supply protection, telecom DC bus clamping, motor drive snubber circuits, and test equipment voltage reference applications requiring stable component supply and RoHS-compliant sourcing.

Supply support for 1SMB5954B-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 and manufacturing operations across Asia and the Americas.

The 1SMB59xxB series belongs to Diodes' high-power Zener diode product line, engineered specifically for reliable voltage regulation and overvoltage protection in industrial, telecom, and automotive power systems where thermal robustness and process consistency are critical.

FAQ

What is the maximum continuous power dissipation for 1SMB5954B-13 at +75°C?

The 1SMB5954B-13 is rated for 3.0 W continuous power dissipation at lead temperature (T_L) = +75°C. Above this temperature, it must be derated at 40 mW/°C. This rating assumes mounting on an FR-4 PCB using Diodes Inc.'s suggested pad layout AP02001, which ensures adequate copper thermal relief.

Does 1SMB5954B-13 have a specified zener impedance at low test currents?

Yes - its dynamic impedance is specified as 700 Ω at I_ZT = 2.3 mA (10% of I_ZM). The datasheet also defines knee impedance (Z_ZK) as 6500 Ω at I_ZK = 1 mA, confirming stable regulation onset above ~1.5 mA and supporting use in low-current reference applications.

Can 1SMB5954B-13 be used in place of a 160 V TVS diode for ESD protection?

No - while it has >16 kV HBM ESD rating, the 1SMB5954B-13 is optimized for regulated DC clamping, not fast transient suppression. Its response time (~100 ns) and clamping ratio (V_BR/V_WM ≈ 1.3) are unsuitable for IEC 61000-4-2 ESD events; dedicated TVS devices like SMBJ160A provide lower clamping voltage and sub-nanosecond response.

What is the thermal resistance from junction to terminal (R_θJT) for 1SMB5954B-13?

The junction-to-terminal thermal resistance is 25 °C/W, measured under conditions defined in Note 5 of DS32125. This value reflects heat conduction through the copper alloy leadframe and is critical for calculating junction temperature when soldered to high-copper thermal pads or heatsinked carriers.