Taiwan Semiconductor Corporation 1SMA4750H

Overview

1SMA4750H from Taiwan Semiconductor is a surface-mount Zener diode engineered for precision voltage regulation and transient overvoltage protection in compact power rails. It delivers a nominal Zener voltage of 27 V at 9.5 mA test current, with dynamic impedance of 35 Ω, maximum power dissipation of 1 W at 25°C, and junction temperature range from –55°C to +175°C - deployed in automotive body control modules requiring stable clamping under load dump conditions.

For engineers reviewing the 1SMA4750H datasheet, 1SMA4750H pinout, 1SMA4750H application, or 1SMA4750H equivalent, key selection criteria include its ±5% V_Z tolerance, low leakage current (≤1 µA at 20.6 V), AEC-Q101 qualification, DO-214AC (SMA) package compatibility with automated placement, and verified surge capability up to 170 A (8.3 ms half-sine).

Technical Context

The 1SMA4750H operates as a single-die, glass-passivated Zener diode optimized for stable reverse-bias breakdown in DC power conditioning circuits. Its 27 V nominal Zener voltage exhibits a temperature coefficient of approximately +6.5 mV/°C (per Fig.8), and it maintains ≤1 µA leakage at 80% of V_Z (20.6 V), supporting low-power standby regulation.

Designed for high-reliability surface-mount applications, the device features matte tin-plated leads compliant with J-STD-002 solderability, meets JESD201 Class 2 whisker resistance, and achieves UL 94V-0 flammability rating in its DO-214AC molding compound - enabling use in thermally constrained automotive PCBs without derating below 60°C ambient.

Key Specifications

Pinout & Package

DO-214AC (SMA) package: molded epoxy case with cathode band marking; matte tin-plated leads; polarity indicated by single black band at cathode end; weight ≈0.060 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMZ27A and BZX84-C27, the 1SMA4750H provides superior surge robustness (30 A vs. 25 A/-), automotive qualification, and thermal resilience (175°C T_J vs. 150°C/150°C), making it the preferred choice for safety-critical 24 V system protection where layout area permits DO-214AC mounting.

Availability

1SMA4750H is available at Aetrix Electronics and suitable for automotive electronics, industrial power supplies, and telecom infrastructure requiring stable component supply with full traceability and lifecycle continuity.

Supply support for 1SMA4750H 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, and protection components with global distribution and AEC-Q101 validation capabilities.

The 1SMA47xxH family was developed specifically for automotive-grade Zener regulation and transient suppression, emphasizing high-temperature reliability, low-inductance packaging, and compatibility with high-volume SMT assembly lines.

FAQ

What is the Zener voltage tolerance for 1SMA4750H?

The 1SMA4750H has a nominal Zener voltage of 27 V with a standard tolerance of ±5%, meaning the actual measured V_Z falls between 25.65 V and 28.35 V when tested at 9.5 mA 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 1SMA4750H datasheet specifies this in the Electrical Specifications table under "Nominal Zener voltage" with Note 1 confirming ±5% as standard.

Is 1SMA4750H suitable for automotive applications?

Yes, the 1SMA4750H is AEC-Q101 qualified and explicitly designed for automotive use. It passes stress tests including high-temperature reverse bias (HTRB), temperature cycling, and mechanical shock per the AEC-Q101 standard. Its –55°C to +175°C junction temperature range, moisture sensitivity level 1, and glass-passivated junction support under-hood deployment. The 1SMA4750H product family documentation confirms qualification status in the FEATURES section on page 1.

What is the maximum surge current rating for 1SMA4750H?

The 1SMA4750H supports a non-repetitive peak forward surge current (I_FSM) of 30 A for an 8.3 ms single half-sine wave, as specified in the Absolute Maximum Ratings table. Additionally, its reverse surge capability reaches 170 A (at 20.6 V) per the Electrical Specifications table's "Surge current" column. These ratings align with ISO 7637-2 Pulse 5a load dump requirements when mounted on a 5 mm × 5 mm Cu pad.

Does 1SMA4750H have halogen-free and RoHS compliance?

Yes, the 1SMA4750H is both RoHS compliant and halogen-free per IEC 61249-2-21. This is confirmed in the FEATURES section of the datasheet, which states "RoHS Compliant" and "Halogen-free according to IEC 61249-2-21". The molding compound and plating materials meet these environmental standards, supporting compliance for export to EU, China, and other regulated markets.

What package type does 1SMA4750H use and what are its key mechanical properties?

The 1SMA4750H uses the DO-214AC (SMA) surface-mount package, with dimensions and pad layout defined in Package Outline Dimensions (page 7). Key mechanical properties include UL 94V-0 flammability-rated epoxy, matte tin-plated leads compliant with J-STD-002, JESD201 Class 2 whisker resistance, and a marked cathode band for polarity identification. Its weight is approximately 0.060 g, and it is supplied in 7,500-unit tape-and-reel format.