Taiwan Semiconductor Corporation 1SMA4743

Overview

1SMA4743 from Taiwan Semiconductor is a 1 W, 13 V ±5% surface-mount Zener diode in DO-214AC (SMA) package, designed for voltage regulation and overvoltage protection in DC power rails, reference circuits, and transient suppression. It delivers 19 mA test current, 10 Ω dynamic impedance at IZT, <1 µA leakage at 9.9 V, and operates across –55°C to +175°C junction temperature.

For engineers reviewing the 1SMA4743 datasheet, 1SMA4743 pinout, 1SMA4743 application, or 1SMA4743 equivalent, key selection criteria include its precise 13 V nominal Zener voltage, low 10 Ω ZzT, robust 30 A non-repetitive surge capability, RoHS/halogen-free compliance, and J-STD-020 Level 1 moisture sensitivity rating for high-yield SMT assembly.

Technical Context

The 1SMA4743 employs a glass-passivated silicon junction optimized for stable reverse-breakdown behavior under regulated DC bias. Its Zener voltage is specified at 13 V with ±5% tolerance, measured at 90 s with lead temperature held at 30°C ±1°C, ensuring repeatability in production testing.

It exhibits low inductance and minimal capacitance (<100 pF at 1 V bias), supporting fast transient response in protection circuits. The device's thermal resistance (R_THJA < 76.8 K/W) enables full 1 W dissipation at 25°C ambient and derated operation up to 1.25 W at 60°C, validated per JEDEC standards.

Key Specifications

Pinout & Package

DO-214AC (SMA) surface-mount package with cathode band marking; matte tin-plated leads compliant with J-STD-002 solderability and JESD 201 Class 2 whisker resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4743A and 1N5243B, the 1SMA4743 provides superior SMT manufacturability, higher surge robustness (30 A vs. 12 A/5 A), and extended thermal range - making it optimal for automotive, industrial, and high-reliability embedded power management.

Availability

1SMA4743 is available at Aetrix Electronics and suitable for DC power rail regulation, overvoltage protection circuits, and precision reference voltage sources requiring stable component supply, consistent parametric performance, and RoHS-compliant sourcing.

Supply support for 1SMA4743 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, rectifiers, Zener diodes, and TVS components for industrial, computing, and consumer applications.

The 1SMA47xx series was engineered specifically for high-volume, high-reliability surface-mount voltage regulation and transient suppression - balancing tight voltage tolerance, low dynamic impedance, and robust surge capability in the industry-standard SMA package.

FAQ

What is the nominal Zener voltage and tolerance of the 1SMA4743?

The 1SMA4743 has a nominal Zener voltage of 13 V with a standard tolerance of ±5%, measured at 19 mA test current (I_ZT) under controlled thermal conditions (lead temperature at 30°C ±1°C). This specification ensures predictable regulation behavior in power supply feedback loops and reference networks where ±0.65 V deviation is acceptable.

Does the 1SMA4743 support automated SMT placement?

Yes, the 1SMA4743 is explicitly designed for automated placement: it features a DO-214AC (SMA) package with matte tin-plated leads compliant with J-STD-002 solderability, J-STD-020 Level 1 moisture sensitivity (no bake required), and polarity indicated by a visible cathode band - all verified in Taiwan Semiconductor's P2102 datasheet.

What is the maximum non-repetitive surge current rating for the 1SMA4743?

The 1SMA4743 supports a peak forward surge current (I_FSM) of 30 A for an 8.3 ms single half-sine wave, per JEDEC standards. This rating applies to transient events such as inrush current or lightning-induced surges, and is validated with the device mounted on a PCB with 5 mm × 5 mm Cu pad area.

How does the 1SMA4743 perform at elevated temperatures?

The 1SMA4743 maintains full 1 W power dissipation up to 25°C ambient and derates linearly to 1.25 W at 60°C, based on R_THJA < 76.8 K/W. Its junction temperature range spans –55°C to +175°C, and leakage current remains <1 µA at 9.9 V even at 125°C - confirmed in the "Typical Leakage Current" curve (Fig.7) of the P2102 datasheet.

Is the 1SMA4743 RoHS and halogen-free compliant?

Yes, the 1SMA4743 is RoHS compliant and halogen-free per IEC 61249-2-21. The molding compound meets UL 94V-0 flammability rating, and terminals pass JESD 201 Class 2 whisker testing - all documented in the Mechanical Data and Features sections of Taiwan Semiconductor's P2102 datasheet.