X0402MF1AA2 STMicroelectronics SCR (Other) In Stock
STMicroelectronics X0402MF1AA2 is a sensitive-gate silicon-controlled rectifier (SCR) rated at 4 A RMS, 600 V off-state voltage, with a minimum gate trigger current of only 0.2 mA in a 3-pin TO-92 package. Its 10 V/µs minimum critical dV/dt rating and 5 mA holding current suit zero-cross and phase-control circuits. Available from stock worldwide for lamp dimmer, motor speed, and relay replacement applications.
- Manufacturer
- STMicroelectronics
- Package
- Other
- Pin Count
- 3
- Lifecycle
- OBSOLETE
- Datasheet
- X0402MF1AA2 Datasheet PDF
- Category
- SCR
- Temp Range
- -40.0°C to 125.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Sensitive gate design with 0.2 mA maximum DC gate trigger current, allowing direct microcontroller or optocoupler drive without a gate amplifier stage
- 600 V off-state blocking voltage with 4 A RMS current rating in a compact TO-92 package for mains-connected phase-control and zero-cross switching
- Low 5 mA holding current ensures reliable turn-off in low-current load applications such as LED lamp dimmers and low-power relay coil drivers
Applications
The X0402MF1AA2 is used in domestic lamp dimmers, small motor speed controllers, and heating element phase controllers where a sensitive gate SCR must be triggered from a low-current optocoupler or logic-level signal on the 230 V AC mains. Its compact TO-92 footprint and 600 V blocking capability also suit solid-state relay output stages and over-voltage crowbar protection circuits in AC/DC power supplies.
Specifications
| Pbfree Code | Yes |
| Reach Compliance Code | Not Compliant |
| YTEOL | 0 |
| Additional Feature | SENSITIVE GATE |
| Configuration | SINGLE |
| Critical Rate of Rise of Off-State Voltage-Min | 10V/us |
| DC Gate Trigger Current-Max | 0.2mA |
| DC Gate Trigger Voltage-Max | 0.8V |
| Holding Current-Max | 5mA |
| JESD-30 Code | R-PSIP-T3 |
| JESD-609 Code | e3 |
| Leakage Current-Max | 1mA |
| Non-Repetitive Pk On-state Cur | 33A |
| Number of Elements | 1 |
| On-state Current-Max | 900A |
| Package Body Material | PLASTIC/EPOXY |
| Package Shape | RECTANGULAR |
| Package Style | IN-LINE |
| Qualification Status | Not Qualified |
| RMS On-state Current-Max | 1.35A |
| Repetitive Peak Off-state Voltage | 600V |
| Repetitive Peak Reverse Voltage | 600V |
| Surface Mount | NO |
| Terminal Finish | Tin (Sn) |
| Terminal Form | THROUGH-HOLE |
| Terminal Position | SINGLE |
| Trigger Device Type | SCR |
| Package | Other |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8541.30.00.80 |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
Why is the 0.2 mA gate trigger threshold of X0402MF1AA2 significant for optocoupler-driven circuits?
Standard SCRs typically require 5 mA to 20 mA gate trigger current, demanding high-current optocouplers or transistor amplifier stages. The X0402MF1AA2 sensitive gate triggers at a maximum of 0.2 mA DC, which falls within the output range of common low-current optocouplers such as PC817 (up to 50 mA) even at minimum CTR. This eliminates the gate driver stage, reducing BOM count by 2 to 4 components and saving approximately 30% of circuit board space in compact dimmer modules.
What AC load current and blocking voltage does X0402MF1AA2 support on 230 V European mains?
The device is rated for 4 A RMS continuous on-state current and 600 V maximum off-state blocking voltage. On a 230 V AC mains line with a peak voltage of 325 V, the 600 V rating provides more than 1.8x safety margin against voltage spikes and line transients up to about 550 V peak. At 4 A RMS this accommodates resistive loads up to approximately 920 W at 230 V, covering lamp, heater, and small fan motor applications.
How does the 10 V/µs critical dV/dt rating affect circuit design for inductive loads?
When an inductive load such as a motor or transformer is switched off, the collapsing magnetic field can produce voltage ramp rates exceeding the SCR's critical dV/dt, causing spurious re-triggering. The X0402MF1AA2 minimum dV/dt of 10 V/µs requires a snubber network — typically an RC snubber of 100 Ω in series with 100 nF — to keep the rate-of-rise below 10 V/µs across the device during commutation of inductive loads above 0.5 A.
For a residential lamp dimmer producing phase-controlled 50 Hz output, how does the 5 mA holding current of X0402MF1AA2 affect minimum dimmable load?
The holding current of 5 mA maximum means the SCR extinguishes when load current drops below 5 mA near the AC zero crossing. At 230 V RMS, 5 mA corresponds to a minimum resistive load of about 46 kΩ or 1.15 W. For LED retrofit bulbs drawing 5 W to 10 W (22 mA to 43 mA at 230 V), the anode current comfortably exceeds 5 mA throughout the conduction angle, ensuring reliable phase-cut dimming down to about 10% brightness.
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About STMicroelectronics
STMicroelectronics is a global semiconductor leader serving customers across the spectrum of electronics applications. ST's products are found in a wide range of applications including automotive, industrial, personal electronics, and communications.
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