Diodes Incorporated 1SMB5914B-13

Overview

1SMB5914B-13 from Diodes Incorporated is a 3.0W surface-mount power Zener diode with nominal zener voltage of 3.6V (min 3.42V, max 3.78V), ±5% tolerance, and 104.2mA maximum zener test current. It features 500Ω maximum zener impedance at test current, 75µA maximum reverse leakage at 1V, and ESD rating >16kV per HBM - used for precision voltage regulation and overvoltage protection in DC power rails.

For engineers reviewing the 1SMB5914B-13 datasheet, 1SMB5914B-13 pinout, 1SMB5914B-13 application, or 1SMB5914B-13 equivalent, key selection criteria include zener voltage accuracy, thermal resistance (226°C/W junction-to-ambient), SMB package compatibility, pulse power handling (up to 1.5kW per 10×1000µs waveform), and RoHS/Green compliance for industrial and automotive board-level designs.

Technical Context

This Zener diode operates in reverse breakdown mode to clamp voltage with stable regulation across temperature (TC of V_Z ≈ −3 mV/°C near 3.6V). Its low dynamic impedance (500Ω @ 9mA) ensures minimal voltage deviation under load transients, while the 3.0W power rating supports sustained dissipation when mounted on FR-4 PCB with recommended pad layout AP02002.

The SMB package enables automated assembly and provides 25°C/W junction-to-terminal thermal resistance at TL = +75°C. Polarity is marked by cathode band; moisture sensitivity level is Level 1 per J-STD-020, and leadframe uses matte tin plating compliant with MIL-STD-202 Method 208 solderability requirements.

Key Specifications

Pinout & Package

SMB package: surface-mount, two-terminal device with cathode band marking on top surface. Terminals are anode (unmarked end) and cathode (band-marked end). Mounting requires conformal pad layout per AP02002 (5.00–5.59mm pad length, 2.00–2.50mm pad width).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5333B and BZX84-C3V6, the 1SMB5914B-13 uniquely balances high-power SMT capability (3.0W), industry-standard SMB footprint, and tight voltage tolerance - making it optimal for automated production of mid-power industrial and automotive boards where thermal and layout constraints preclude larger packages or lower-rated alternatives.

Availability

1SMB5914B-13 is available at Aetrix Electronics and suitable for industrial power monitoring, automotive body control modules, medical sensor interfaces, and consumer IoT battery management systems requiring stable component supply with full traceability and lifecycle continuity.

Supply support for 1SMB5914B-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 centers across Asia and manufacturing in China, Taiwan, and the U.S.

This part belongs to the 1SMB59xxB series of high-power Zener diodes designed specifically for surface-mount voltage regulation and transient suppression in space-constrained, high-reliability power systems.

FAQ

What is the maximum continuous zener current for 1SMB5914B-13 at 25°C ambient?

The maximum continuous zener current is calculated from P_D / V_Z: 550mW / 3.6V ≈ 153mA at T_A = +25°C. However, the rated test current is 9mA, and operation above 104.2mA requires thermal derating per the 4.4mW/°C curve above +25°C to avoid exceeding junction temperature limits.

Does 1SMB5914B-13 require a heatsink for 3.0W operation?

No heatsink is required for 3.0W operation at T_L = +75°C (lead temperature), provided the PCB follows Diodes Inc.'s AP02002 pad layout on FR-4 with ≥1 oz copper. At T_A = +25°C, full 3.0W is not sustainable due to R_θJA = 226°C/W - maximum ambient is ~75°C for 3.0W continuous use.

How does the −3 mV/°C temperature coefficient affect regulation accuracy over −40°C to +125°C?

Over that range, V_Z shifts by approximately −0.5V (−3 mV/°C × 165°C), resulting in a total span of ~3.1V to 4.1V. For applications requiring tighter stability, this drift must be compensated in system calibration or combined with temperature-sensing feedback loops.

Can 1SMB5914B-13 be used as a substitute for a 3.3V Zener in legacy designs?

No - its nominal 3.6V rating exceeds typical 3.3V rail tolerance (±5% = 3.135–3.465V). Using it risks undervoltage lockout or incorrect sensing. For 3.3V systems, 1SMB5913B (3.3V nominal) is the correct variant with matching 3.13–3.47V range and identical package/characteristics.