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
What are the key features of X0402MF1AA2?
- 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
What is X0402MF1AA2 used for?
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.
What are the specifications of X0402MF1AA2?
| 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 |
Where can I find the X0402MF1AA2 datasheet?
X0402MF1AA2 Datasheet DownloadOfficial datasheet from STMicroelectronics
What are equivalent replacements for X0402MF1AA2?
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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