STMicroelectronics STIEC45-30ACS

Overview

STIEC45-30ACS from STMicroelectronics is a bidirectional Transil™ TVS diode designed for IEC 61000-4-5 Level 4 surge protection on DC power lines, with 30 V stand-off voltage, 55 V clamping voltage at 500 A (8/20 μs), and 0.2 μA leakage at 25 °C. It operates up to 150 °C junction temperature and is housed in an SMC (DO-214AB) package compliant with JEDEC and IPC 7351.

For engineers reviewing the STIEC45-30ACS datasheet, STIEC45-30ACS pinout, STIEC45-30ACS application, or STIEC45-30ACS equivalent, key selection criteria include bidirectional clamping symmetry, 500 A peak pulse current capability at T_j = 150 °C, low dynamic resistance (0.036 Ω), and compliance with IEC 61000-4-2 Level 4 ESD and MIL-STD-883H HBM (25 kV).

Technical Context

The STIEC45-30ACS employs planar silicon technology to achieve stable breakdown behavior and low leakage across temperature - critical for high-reliability SMPS and industrial power supplies. Its bidirectional architecture ensures symmetrical clamping at ±33.3–36.8 V (V_BR) and ≤55 V (V_CL) under 500 A surge, enabling robust protection against common-mode surges per IEC 61000-4-5 Level 4 (4 kV, R = 12 Ω).

Thermal performance is optimized via low junction-to-leads thermal resistance (15 °C/W) and validated PCB pad layout per IPC 7351, supporting sustained operation at T_j = 150 °C while maintaining clamping integrity. Dynamic resistance of 0.036 Ω directly determines residual clamping rise under high-current transients.

Key Specifications

Pinout & Package

The STIEC45-30ACS is housed in an SMC package (JEDEC DO-214AB), with two terminals in a gull-wing surface-mount configuration. The package features a 5.55–6.25 mm body length (D), 7.75–8.15 mm width (E), and 1.90–2.45 mm height (A1), optimized for high-power dissipation and automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional TVS protection applications.

Compared with SMBJ30CA and SMCJ30CA, STIEC45-30ACS delivers superior surge headroom (55 V clamping at 500 A) in the same SMC footprint, enabling tighter voltage margins in 3.3 V/5 V logic protection schemes while maintaining 0.2 μA leakage for ultra-low-power applications.

Availability

STIEC45-30ACS is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, automotive body control modules, and PLC I/O modules requiring stable component supply and full IEC 61000-4-5 Level 4 compliance.

Supply support for STIEC45-30ACS 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

The Transil™ TVS series targets high-reliability surge protection in harsh environments, with STIEC45-30ACS specifically engineered for DC power line immunity per IEC 61000-4-5 Level 4 and extended temperature operation up to 150 °C.

FAQ

What is the maximum clamping voltage of STIEC45-30ACS at 300 A (8/20 μs)?

Using the specified dynamic resistance (R_D = 0.036 Ω) and maximum breakdown voltage (V_BR(max) = 36.8 V), the calculated clamping voltage is V_CL = (0.036 Ω × 300 A) + 36.8 V = 47.6 V. This matches typical curve data showing ~47–48 V at 300 A, confirming predictable voltage limiting below 55 V.

Can STIEC45-30ACS be used in place of a unidirectional TVS like STIEC45-30AS?

No - STIEC45-30ACS is bidirectional and clamps symmetrically in both polarities, whereas STIEC45-30AS is unidirectional and only clamps in reverse bias. Substitution requires verifying circuit topology: bidirectional use is mandatory for floating or AC-coupled lines; unidirectional is sufficient for grounded DC rails with defined polarity.

Does STIEC45-30ACS meet UL 94 V0 flammability requirements?

Yes - the device's molded resin housing complies with UL 94 V0, as confirmed in the datasheet (Section "Complies with the following standards"). This ensures self-extinguishing behavior under flame exposure, supporting safety certification in industrial and telecom end equipment.

What is the recommended PCB pad layout for optimal thermal performance?

The datasheet specifies an IPC 7351-compliant SMC footprint with copper surface area ≥4.0 cm² per lead (Figure 10). Minimum pad dimensions are 6.6 mm × 7.75 mm per terminal, using 35 μm copper thickness on FR4. This layout achieves R_th(j-a) = 90 °C/W and supports continuous 150 °C operation under rated surge conditions.