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Home > Products > Discrete Semiconductor Products > Thyristors > SCRs

STMicroelectronics X0405MF0AA2

Name: X0405MF0AA2
Brand: STMicroelectronics
SKU: X0405MF0AA2
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: X0405MF0AA2

Manufacturer:: STMicroelectronics

Category:: SCRs

Package:: TO-202 No Tab

Datasheet:: X0405MF0AA2.pdf

Description:: SCR 4A 600V TO202-3

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Product details

Overview

X0405MF0AA2 from STMicroelectronics is a sensitive 4A, 600V RMS SCR with ultra-low gate trigger current (IGT ≤ 50 µA), designed for gate-current-limited triggering in capacitive discharge ignition circuits, low-power overvoltage crowbar protection, and motor control in battery-powered kitchen appliances. It features VDRM = 600 V, IT(RMS) = 4 A at T_L = 60°C, and TO-202-3 package.

For engineers reviewing the X0405MF0AA2 datasheet, X0405MF0AA2 pinout, X0405MF0AA2 application, or X0405MF0AA2 equivalent, key selection criteria include gate sensitivity (≤50 µA), dV/dt immunity (≥15 V/µs at T_j = 110°C), holding current (≤5 mA), on-state voltage (≤1.8 V at 8 A), and thermal resistance R_th(j–l) = 15 °C/W.

Technical Context

This SCR operates as a latching unidirectional switch triggered by minimal gate current, enabling reliable turn-on even with weak drive sources such as RC networks or microcontroller GPIOs via high-value gate resistors. Its low I_GT (max 50 µA) and high dV/dt immunity (min 15 V/µs) ensure noise-immune operation in noisy industrial and appliance environments.

The device uses planar passivated silicon technology with optimized gate-cathode geometry to achieve stable triggering across –40°C to +125°C junction temperature. It supports non-repetitive surge currents up to 30 A (10 ms) and fusing I²t of 4.5 A²s, making it suitable for transient overvoltage clamping without external snubbers.

Key Specifications

Parameter	Value and Actual Design Meaning
VDRM / VRRM	600 V - Maximum repetitive off-state blocking voltage in either direction; defines maximum AC line or DC bus voltage it can safely block.
IT(RMS)	4 A at T_L = 60°C - Continuous RMS on-state current capability with heatsink; derates to 1.35 A at ambient 25°C without heatsink.
IGT (max)	50 µA - Maximum gate trigger current required; enables direct drive from low-power logic or high-impedance timing circuits.
dV/dt (min)	15 V/µs at T_j = 110°C - Minimum rate of rise of off-state voltage before false triggering; ensures immunity to fast transients in SMPS or motor drives.
VTM (max)	1.8 V at I_TM = 8 A - Peak on-state voltage drop; determines conduction loss and self-heating under load.
R_th(j–l)	15 °C/W - Junction-to-leads thermal resistance; defines minimum heatsinking requirement for sustained 4 A operation.

Pinout & Package

Package: TO-202-3 (plastic, 3-lead, through-hole). Leads are Anode (A), Cathode (K), and Gate (G), with lead spacing matching JEDEC TO-202 outline.

Pin/Terminal	Circuit Role	Design Meaning
Anode (A)	Main current entry terminal during conduction	Connected to positive side of AC/DC supply; carries full load current when triggered; must be isolated from PCB ground plane per creepage requirements.
Cathode (K)	Main current exit terminal and reference for gate drive	Common return path for load current; gate signal referenced to this node; requires low-inductance layout to maintain dV/dt immunity.
Gate (G)	Control input for turn-on initiation	Accepts µA-level current pulses; sensitive to ESD; requires series resistor (typically 1–10 kΩ) to limit I_GM and stabilize triggering.

Key Features

Feature	Design Value
Ultra-low gate trigger current	IGT ≤ 50 µA ensures compatibility with microcontroller GPIOs, RC timing networks, and low-power comparators without buffer stages.
High dV/dt immunity	15 V/µs minimum prevents false triggering from switching noise in motor drives or SMPS feedback loops.
Low on-state voltage	VTM ≤ 1.8 V at 8 A reduces conduction losses and thermal stress in compact, fanless designs.
Robust surge rating	30 A non-repetitive surge (10 ms) and 4.5 A²s I²t support single-event overvoltage crowbar protection without external fuses.

Applications

Capacitive Discharge Ignition (CDI)

Low-Power Crowbar Protection

Use Scenario: Triggering high-voltage spark generation in small gasoline engines (e.g., lawnmowers, chainsaws) using stored capacitor energy.

IC Role / Device Role / Timing Role: SCR acts as the main discharge switch, turning on within nanoseconds upon gate pulse to release capacitor energy into ignition coil.

Use Value: 50 µA I_GT allows direct triggering from low-energy timing circuits; 600 V VDRM withstands flyback spikes up to 400 V.

Use Scenario: Overvoltage shutdown in 12 V/24 V DC power supplies for embedded controllers or sensors.

IC Role / Device Role / Timing Role: SCR placed across output rail; triggered by Zener+transistor monitor circuit when voltage exceeds threshold.

Use Value: Fast turn-on and 30 A surge rating enable immediate short-circuit clamping; low V_TM minimizes power dissipation during crowbar event.

Kitchen Appliance Motor Control

AC Phase-Angle Dimmer Interface

Use Scenario: Speed control of universal motors in blenders, mixers, and food processors powered from rectified AC.

IC Role / Device Role / Timing Role: SCR used in half-wave or full-wave phase-controlled topology, gated by zero-crossing detector and timing capacitor.

Use Value: Low I_GT permits use of high-value RC timing networks; TO-202-3 package allows direct PCB mounting with minimal heatsinking.

Use Scenario: Interface between microcontroller PWM output and mains-connected resistive loads (e.g., heating elements, lamps).

IC Role / Device Role / Timing Role: SCR serves as AC line switch synchronized to zero-crossing; gate driven via optocoupler-isolated pulse.

Use Value: 15 V/µs dV/dt immunity prevents misfiring due to optocoupler delay or line noise; 4 A IT(RMS) supports up to 500 W resistive load.

Equivalent & Alternatives

The following parts are listed as comparable options for similar SCR switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BT169G	IGT max = 200 µA; VDRM = 400 V; IT(RMS) = 0.8 A	Lower voltage/current rating; suited only for sub-100 W loads and <300 V systems	Select only if gate drive >200 µA is available and system voltage ≤400 V.
TIC226M	IGT max = 50 µA; VDRM = 600 V; IT(RMS) = 4 A; TO-220 package	Same electrical specs but larger TO-220 footprint and higher R_th(j–l) (20 °C/W)	Choose when higher thermal margin is needed and board space allows TO-220 mounting.

Compared with BT169G and TIC226M, X0405MF0AA2 uniquely combines 50 µA sensitivity, 600 V blocking, 4 A RMS rating, and TO-202-3 compactness-making it optimal for space-constrained, low-drive, mains-connected crowbar and ignition systems where thermal density matters.

Availability

X0405MF0AA2 is available at Aetrix Electronics and suitable for capacitive discharge ignition systems, low-power overvoltage crowbar protection circuits, and kitchen appliance motor control requiring stable component supply and long-term manufacturing continuity.

Supply support for X0405MF0AA2 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The X04 Series belongs to ST's high-sensitivity SCR product line, engineered specifically for gate-current-constrained applications including ignition, crowbar, and phase-control where conventional SCRs fail to trigger reliably.

FAQ

What is the maximum allowable gate-cathode resistance for reliable triggering?

The datasheet specifies that I_GT remains ≤50 µA with R_GK = 1 kΩ at T_j = 25°C. For guaranteed turn-on across temperature, R_GK should not exceed 470 Ω - verified by Fig. 5 showing I_H increase above 1 kΩ. Higher values risk failure to latch under cold conditions or aging.

Can X0405MF0AA2 be used in AC line-switching without a snubber network?

Yes - its 15 V/µs dV/dt immunity (min, at T_j = 110°C) and low I_GT allow snubberless operation in resistive or lightly inductive loads (e.g., heaters, incandescent lamps). However, snubbers remain recommended for highly inductive loads like universal motors to prevent commutation failure.

What is the minimum holding current (I_H) at 125°C junction temperature?

Per Fig. 4, I_H increases with temperature: typical value is ~3.5 mA at 125°C, with maximum specified as 5 mA at T_j = 125°C and R_GK = 1 kΩ. This defines the lowest load current that sustains conduction after triggering.

Is X0405MF0AA2 RoHS compliant and halogen-free?

Yes - STMicroelectronics confirms X0405MF0AA2 meets RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. The "F" suffix in the part number denotes lead-free finish, and the TO-202-3 package uses environmentally compliant molding compound.

X0405MF0AA2 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: X04

Package/Case:: TO-202 No Tab

Packaging:: Tube

Product Status:: Obsolete

Voltage - Off State:: 600 V

Voltage - Gate Trigger (Vgt) (Max):: 800 mV

Current - Gate Trigger (Igt) (Max):: 50 µA

Voltage - On State (Vtm) (Max):: 1.8 V

Current - On State (It (AV)) (Max):: 900 mA

Current - On State (It (RMS)) (Max):: 1.35 A

Current - Hold (Ih) (Max):: 5 mA

Current - Off State (Max):: 5 µA

Current - Non Rep. Surge 50, 60Hz (Itsm):: 33A, 30A

SCR Type:: Sensitive Gate

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-202-3

X0405MF0AA2 FAQ

1.How can I place an order for X0405MF0AA2 through Aetrix?

Please submit a Request for Quotation (RFQ) for X0405MF0AA2 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for X0405MF0AA2 reliable?

The price and inventory of X0405MF0AA2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for X0405MF0AA2 is usually 5 days.

3.What payment methods are accepted for X0405MF0AA2?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for X0405MF0AA2 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for X0405MF0AA2?

X0405MF0AA2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your X0405MF0AA2 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for X0405MF0AA2?

For technical support, including X0405MF0AA2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your X0405MF0AA2 requirements.

6.How does Aetrix verify that X0405MF0AA2 is sourced from the original manufacturer or authorized distributors?

All X0405MF0AA2 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that X0405MF0AA2 meets industry standards.

7.What is the process for return or replacement of X0405MF0AA2?

All X0405MF0AA2 units undergo pre-shipment inspection (PSI). If there is an issue with X0405MF0AA2, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The X0405MF0AA2 part is unused and in its original packaging.

Return procedure for X0405MF0AA2:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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