Taiwan Semiconductor Corporation 1SMA4750

Overview

1SMA4750 from Taiwan Semiconductor is a surface-mount 1 W Zener diode with a nominal zener voltage of 27 V, test current of 9.5 mA, dynamic impedance of 35 Ω at IZT, maximum leakage current of 1 µA at 20.6 V, and DO-214AC (SMA) package. It serves as a precision voltage reference and overvoltage protection device in DC power rails and analog signal conditioning circuits.

For engineers reviewing the 1SMA4750 datasheet, 1SMA4750 pinout, 1SMA4750 application, or 1SMA4750 equivalent, key selection criteria include its ±5% VZ tolerance, 175°C maximum junction temperature, low-inductance glass-passivated junction, moisture sensitivity level 1 rating, and compliance with RoHS and halogen-free standards per IEC 61249-2-21.

Technical Context

The 1SMA4750 operates as a single-die, unidirectional Zener diode optimized for stable reverse-bias regulation under steady-state and transient conditions. Its 35 Ω dynamic impedance at 9.5 mA ensures predictable clamping behavior, while the 750 Ω knee impedance at 1 mA supports reliable low-current regulation.

Thermal performance is defined by a 175°C maximum junction temperature and 1 W power dissipation at 25°C ambient, derating linearly to 1.25 W at 60°C when mounted on PCB with Cu-pad size 5 mm × 5 mm and RTHJA < 76.8 K/W. Non-repetitive peak surge capability reaches 60 W for 100 µs pulses.

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), surface-mount, single-anode/cathode configuration with cathode band marking. Weight: 0.060 g. Molding compound meets UL 94V-0 flammability rating; matte tin-plated leads comply 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 1N4750A and BZX84-C27, the 1SMA4750 delivers higher power density (1 W in DO-214AC), superior surge robustness (60 W vs. ~10 W), and SMT manufacturability-making it optimal for industrial power regulation and automotive-grade transient suppression where reliability and automation readiness are critical.

Availability

1SMA4750 is available at Aetrix Electronics and suitable for DC power supply regulation, overvoltage protection circuits, and analog signal reference applications requiring stable component supply, consistent parametric performance, and RoHS-compliant sourcing.

Supply support for 1SMA4750 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 markets.

The 1SMA47xx series is designed specifically for high-reliability surface-mount voltage regulation and transient suppression in space-constrained, thermally demanding environments-emphasizing low-inductance packaging, stable VZ tolerance, and robust surge immunity.

FAQ

What is the nominal zener voltage and tolerance of the 1SMA4750?

The 1SMA4750 has a nominal zener voltage of 27 V with a standard tolerance of ±5%, measured at 9.5 mA test current (IZT) and 30°C lead temperature. This tolerance is guaranteed per JEDEC registration and applies across the full operating temperature range of –55°C to +175°C. The 1SMA4750 datasheet specifies VZ = 27 V ±5% under these standardized test conditions.

What is the maximum power dissipation of the 1SMA4750 at 60°C ambient temperature?

The 1SMA4750 delivers 1.25 W maximum power dissipation at TA = 60°C when mounted on a PCB with a 5 mm × 5 mm copper pad and thermal resistance RTHJA < 76.8 K/W. This derated value reflects linear thermal derating from 1 W at 25°C ambient, supporting reliable operation in enclosed industrial enclosures where ambient temperatures exceed typical room conditions.

Does the 1SMA4750 meet RoHS and halogen-free requirements?

Yes, the 1SMA4750 is RoHS compliant and halogen-free per IEC 61249-2-21. These certifications are explicitly stated in the official Taiwan Semiconductor datasheet (Version P2102) and verified through material declarations. The device contains no lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE), and bromine/chlorine content is below threshold limits.

What is the non-repetitive peak surge power rating for the 1SMA4750?

The 1SMA4750 has a non-repetitive peak surge power rating (PZSM) of 60 W for a 100 µs square pulse at 25°C ambient, as defined in the Absolute Maximum Ratings table. This rating enables effective clamping of fast transients such as ESD and inductive switching spikes without permanent degradation, provided pulse repetition remains infrequent and thermal recovery time is observed.

What package type and marking code does the 1SMA4750 use?

The 1SMA4750 uses the DO-214AC (SMA) surface-mount package and is marked with the code "750A" on the cathode band side. This marking aligns with Taiwan Semiconductor's standardized coding scheme for the 1SMA47xx family, where "750" corresponds to the 27 V zener voltage and "A" denotes ±5% tolerance. The package features matte tin-plated leads and UL 94V-0 molding compound.