Product Overview
The ST90E125 is a high-current TRIAC (Triode for Alternating Current) designed for AC power control applications. Manufactured by STMicroelectronics, this device features 12A RMS current handling capability with 800V blocking voltage, making it suitable for medium-power AC switching circuits. The TO-220AB package provides excellent thermal performance for through-hole mounting, and the device supports four-quadrant triggering for flexible control design. It is intended for use in industrial motor control, heating systems, lighting dimmers, and home appliances.
Key Specifications
| Type | TRIAC (Bidirectional Thyristor) |
| RMS On-State Current (IT(RMS)) | 12 A |
| Repetitive Peak Voltage (VDRM/VRRM) | 800 V |
| Gate Trigger Current (IGT) | 35 mA max (all quadrants) |
| Gate Trigger Voltage (VGT) | 1.5 V max |
| Holding Current (IH) | 50 mA max |
| Non-Repetitive Surge Current (ITSM) | 120 A |
| Maximum Junction Temperature | 125 °C |
| Package | TO-220AB |
| Insulating Tab | Yes (insulated package) |
Features
- 12A RMS current, 800V blocking voltage
- Four-quadrant triggering capability
- Insulated TO-220AB package (2.5kV isolation)
- High noise immunity (high static dV/dt)
- Snubberless operation capability
- Glass passivated junctions for reliability
- UL recognized (E62272)
- RoHS compliant and halogen-free
- Direct replacement for BTA12 series
Applications
- AC motor speed control
- Industrial heating systems
- Lighting dimmers and ballasts
- Solid state relays (SSR)
- Home appliances (washing machines, dishwashers)
- Inrush current limiting
- AC power switches
- Welding equipment