| Image | Part Number | Description / PDF | Quantity | Rfq |
|---|---|---|---|---|
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Panasonic |
DIAC 28-36V 2A DO35 |
0 |
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DIACs (Diodes for Alternating Current) and SIDACs (Silicon Diodes for Alternating Current) are bidirectional trigger devices used primarily to control thyristor-based circuits. These three-layer semiconductor devices exhibit negative resistance characteristics and are critical in AC power control systems. They enable precise switching of high-voltage AC loads through their unique breakover voltage behavior, making them essential in lighting, motor control, and industrial automation applications.
| Type | Functionality | Application Examples |
|---|---|---|
| DIAC | Low-power bidirectional trigger diode with symmetrical breakover voltage | TRIAC gate triggering in dimmer switches |
| SIDAC | Higher current/voltage capability with precise voltage clamping | Industrial motor speed controllers |
| Programmable DIAC | Voltage-adjustable triggering through external resistors | Customizable power control systems |
DIACs/SIDACs typically consist of a four-layer (PNPN) silicon structure with two main terminals (A1/A2). The symmetrical doping profile creates a negative resistance region during reverse bias. Advanced devices incorporate:
| Parameter | Description | Importance |
|---|---|---|
| Breakover Voltage (VBO) | Voltage threshold for conduction (typically 20-32V) | Determines triggering point |
| Trigger Current (IT) | Minimum current to sustain conduction | Impacts load compatibility |
| Holding Current (IH) | Current level to maintain on-state | Affects circuit stability |
| Peak Current (IPT) | Maximum transient current capability | Overload protection |
| dv/dt | Voltage change rate immunity | Prevents false triggering |
Key industries and equipment:
Example: DIACs in phase-control dimmers trigger TRIACs at specific AC cycle points to adjust light intensity.
| Manufacturer | Product Series | Key Features |
|---|---|---|
| STMicroelectronics | DB3 | Standard DIAC with 32V VBO |
| ON Semiconductor | SIDAC103 | 100V, 3A industrial SIDAC |
| Vishay | TECC94 | High surge current capability |
Key considerations:
Emerging developments:
Market growth driven by energy-efficient lighting and industrial automation demands.