TRIAC (Triode for Alternating Current) is a three-terminal semiconductor device belonging to the thyristor family. It enables bidirectional current flow control in AC circuits through a single gate terminal. As a key component in power electronics, TRIACs are widely used for phase control, switching, and regulation of AC loads. Their ability to conduct current in both directions makes them ideal for applications requiring full-wave control, such as dimmers and motor speed regulators.
| Type | Functional Characteristics | Application Examples |
|---|---|---|
| Standard TRIAC | General-purpose with moderate gate sensitivity | Light dimmers, heater controls |
| Sensitive Gate TRIAC | Low gate trigger current ( 5mA) | Microcontroller-driven circuits |
| Logic Level TRIAC | Compatible with 3.3V/5V logic signals | Smart home automation systems |
| High dv/dt TRIAC | Enhanced immunity to voltage spikes | Industrial motor drives |
TRIACs feature a four-layer (PNPN) silicon structure with three electrodes: Main Terminal 1 (MT1), Main Terminal 2 (MT2), and Gate (G). The symmetrical design allows bidirectional conduction. Modern TRIACs incorporate:
| Parameter | Description | Typical Range |
|---|---|---|
| Breakover Voltage (VBO) | Minimum voltage to initiate conduction | 200-1200V |
| Gate Trigger Current (IGT) | Required gate current for turn-on | 5-50mA |
| Holding Current (IH) | Minimum current to maintain conduction | 5-50mA |
| RMS On-State Current (IT(RMS)) | Continuous load current capacity | 0.5-50A |
| dv/dt Rating | Voltage change immunity | 10-50V/ s |
| Manufacturer | Representative Product | Key Parameters |
|---|---|---|
| STMicroelectronics | BT136-600E | 600V, 4A, 10mA IGT |
| ON Semiconductor | Q6015LH | 600V, 15A, 15mA IGT |
| Infineon Technologies | BTA16-600B | 600V, 16A, 50mA IGT |
| Microsemi | MAC97A8 | 600V, 8A, 5mA IGT |
Key development trends include:
Market growth is driven by smart grid implementations and EV charging infrastructure expansion, with a projected CAGR of 6.8% through 2030.