ACST435-8B

Overview

The ACST435-8B is a Snubberless Triac from STMicroelectronics, rated for 4A RMS current and 800V blocking voltage. It features a maximum junction temperature of 150°C and operates in three quadrants. Key electrical parameters include a holding current of up to 45mA, gate trigger voltage of 1V, and gate trigger current of 35mA. The device exhibits low on-state voltage of 1.5V and leakage current of 5µA at VDRM. Packaged in D2PAK-3 (TO-263), it supports surface mount installation with a working temperature range from -40°C to +150°C.

Feature Summary

• Snubberless technology enables direct switching of AC inductive loads without external RC snubber circuits
• High static dV/dt immunity reduces risk of false turn-on during rapid voltage transients
• Enhanced dynamic commutation performance ensures reliable turn-off under high di/dt conditions
• Extended thermal capability allows operation up to 150°C junction temperature

Applications

• AC inductive load switching in universal motor controls
• Electro valve actuation systems
• Kitchen appliance power control modules
• Power tool speed regulation circuits
• Dishwasher motor drive interfaces

Procurement Notes

Verify the specific suffix '8B' against official STMicroelectronics documentation to confirm pinout compatibility and package variant. Confirm RoHS and halogen-free compliance status via the latest datasheet revision. Ensure ordering quantities align with manufacturer tube packaging specifications. Validate that the component meets required industrial or consumer grade standards for the intended application environment.

Selection Notes

Select this component when high commutation capability is required for AC inductive loads without snubber circuitry. The 4A RMS rating suits moderate power applications like small motors and valves. The 800V voltage rating provides adequate margin for standard AC line voltages. Consider the D2PAK package for surface mount assembly needs requiring robust thermal dissipation through the tab.

Part Context

The ACST435-8B belongs to ST’s T-Series Snubberless Triacs, designed for logic-level triggering and high reliability. This series integrates advanced silicon technology to eliminate external snubbers, simplifying PCB layout. It complements other ACST and BTA series devices, offering a balance of current handling and voltage blocking for general-purpose AC switching tasks in household and industrial equipment.

Replacement Considerations

Publicly confirmed substitutes include T435-800B and Z0409MF. Verify pinout and thermal characteristics before substitution. Other compatible parts may include BTA04-600B or similar 4A Snubberless Triacs from alternative manufacturers, provided electrical ratings match or exceed original specifications.