STMicroelectronics ACS120-7SH

Overview

ACS120-7SH from STMicroelectronics is a DPAK-packaged AC line switch with ±700 V blocking voltage, 2 A RMS on-state current, and integrated avalanche clamping (V_CL = 1100 V). It functions as a high-noise-immunity solid-state relay replacement in appliance control systems, directly driven by microcontrollers via negative gate current, and eliminates external snubbers for inductive loads up to 2 A.

For engineers reviewing the ACS120-7SH datasheet, ACS120-7SH pinout, ACS120-7SH application, or ACS120-7SH equivalent, this device is selected for IEC 61000-4-5-compliant AC static switching in washing machines, dishwashers, and HVAC defrost heaters where gate kickback suppression, thermal robustness, and direct MCU interface are critical design requirements.

Technical Context

The ACS120-7SH implements the ASD™ architecture: a monolithic high-voltage switch integrating a clamping diode and gate-level shifter driver. Its negative-gate-triggering logic isolates digital controllers from mains-referenced power paths while sustaining 2 kV non-repetitive line pulses per IEC 61000-4-5.

It operates across -30 °C to +125 °C junction temperature, supports 50–60 Hz full-cycle conduction, and achieves >500 V/µs static dV/dt immunity at 110 °C - enabling reliable turn-off of inductive loads (e.g., solenoids, fans) without external protection components.

Key Specifications

Pinout & Package

DPAK (TO-252) package with exposed thermal pad for PCB heat sinking; 3-terminal configuration optimized for surface-mount assembly and high-current trace routing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar AC line switching applications.

Compared with ACS108-7SH and LIA120S, the ACS120-7SH delivers higher current capacity with fully integrated clamping and gate drive - reducing total solution size, bill-of-materials count, and validation effort for new appliance designs requiring robust 2 A AC switching.

Availability

ACS120-7SH is available at Aetrix Electronics and suitable for washing machine control modules, dishwasher solenoid drivers, and HVAC defrost heater circuits requiring stable component supply, long-term lifecycle support, and compliance with IEC 61000-4-5 surge standards.

Supply support for ACS120-7SH 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, specializing in power management, analog, and automotive-grade ICs with vertical manufacturing capability and AEC-Q100 qualification expertise.

The ACS™ AC line switch product line was developed specifically for high-reliability, low-BOM-count AC load control in white goods - integrating clamping, noise immunity, and MCU interface into single-package solid-state relays.

FAQ

What is the maximum allowable gate current for ACS120-7SH?

The peak gate current (I_GM) is rated at 1 A for 20 µs pulses. Continuous gate current must remain below 10 mA (I_GT max), and average gate power dissipation is limited to 0.1 W. Exceeding these values risks gate oxide damage or premature latch-up during switching transitions.

Can ACS120-7SH replace an electromechanical relay in a 230 VAC, 2 A fan circuit?

Yes - it supports 2 A RMS at 50/60 Hz with thermal resistance of 2.6 °C/W (junction-to-lead), enabling direct PCB mounting without heatsinks for typical fan loads. Its 1100 V clamping voltage safely absorbs inductive kickback, and >500 V/µs dV/dt immunity prevents false triggering during motor commutation noise.

Does ACS120-7SH require a heatsink when operating at 2 A RMS?

No external heatsink is required if the PCB provides ≥0.5 cm² of 35 µm copper under the exposed thermal pad. At T_c = 115 °C, the device sustains 2 A RMS with R_th(j-a) = 70 °C/W - meaning ambient temperature must stay ≤65 °C for safe operation without forced cooling.

How does ACS120-7SH achieve IEC 61000-4-5 compliance?

It passes Level 3 (2 kV line-earth, 1 kV line-line) surge testing per IEC 61000-4-5 by clamping transient voltages to 1100 V using its internal avalanche structure. The test uses R = 150 Ω, L = 10 µH, and V_PP = 2 kV - and the device sustains ten such pulses per polarity without degradation or latch-up.