Thyristors - TRIACs

Image	Part Number	Description / PDF	Quantity	Rfq
	CQ202-4DS Central Semiconductor	TRIAC 4A TH TO-202-2	0
	CQ218-45D Central Semiconductor	TRIAC 45A 400V TO-218	0
	CQ218-45B Central Semiconductor	TRIAC 45A 200V TO-218	0
	CQ48-25M Central Semiconductor	TRIAC 25A 600V TO-48	0
	CQD-4M TR13 Central Semiconductor	SMT TRIAC	0
	CQ220-25MFP Central Semiconductor	TRIAC 25A TO-220	0
	CQ3P-40D Central Semiconductor	TRIAC 40A 400V TO-3	0
	CQ220L-8DS Central Semiconductor	TRIAC A TO-220	0
	CQ220-16MFP Central Semiconductor	TRIAC 16A TO-220	0
	CQ218I-25M Central Semiconductor	TRIAC 25A 600V TO-218	0
	CQ218I-40M Central Semiconductor	TRIAC 40A 600V TO-218	0
	CS3P-40D Central Semiconductor	TRIAC 40A 400V TO-3	0
	CQ218-45N Central Semiconductor	TRIAC 45A 800V TO-218	0
	CQ220I-6D Central Semiconductor	TRIAC A TO-220	0
	CQ220-8MFP Central Semiconductor	TRIAC 8A TO-220	0
	CQ218-45M Central Semiconductor	TRIAC 45A 600V TO-218	0
	CQ3P-25D Central Semiconductor	TRIAC 25A 400V TO-3	0
	CQ220-8DS Central Semiconductor	TRIAC 8A TO-220	0
	CQ3P-40N Central Semiconductor	TRIAC 40A 800V TO-3	0
	CQ3P-40M Central Semiconductor	TRIAC 40A 600V TO-3	0

Thyristors - TRIACs

1. Overview

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.

2. Main Types and Functional Classification

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

3. Structure and Composition

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:

Dielectric passivation layers for voltage stability
Aluminum gate metallization
Epitaxial silicon wafers with precise doping profiles
Plastic encapsulation (TO-220/TO-92 packages)

4. Key Technical Parameters

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

5. Application Fields

Consumer Electronics: Smart lighting systems, washing machine water level controls
Industrial Automation: AC motor speed controllers, solid-state relays
Power Systems: Voltage regulators, reactive power compensators
Automotive: Electric vehicle charging circuits, HVAC controls
Renewable Energy: Solar inverter AC switching circuits

6. Leading Manufacturers and Products

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

7. Selection Guidelines

Verify VBO exceeds maximum circuit voltage by 20%
IT(RMS) should be 1.5 load current
Match IGT with driver circuit capability
Consider heatsinking requirements
Select dv/dt rating based on load inductance
Use zero-crossing detection for EMI-sensitive applications

8. Industry Trends

Key development trends include:

Integration with SiC/GaN for higher efficiency
Smart packaging with built-in temperature sensors
Miniaturization for space-constrained applications
Improved immunity to electromagnetic interference
AI-driven predictive maintenance in industrial systems

Market growth is driven by smart grid implementations and EV charging infrastructure expansion, with a projected CAGR of 6.8% through 2030.