STMicroelectronics X0202MA 2BL2

Overview

X0202MA 2BL2 from STMicroelectronics is a sensitive-gate silicon-controlled rectifier (SCR) rated for 1.25 A RMS on-state current and 600 V repetitive peak off-state voltage, housed in a TO-92 package with 3 terminals (Anode, Cathode, Gate). It features low trigger gate current (50–200 µA), high dV/dt immunity (≥10 V/µs), and optimized forward voltage drop (≤1.45 V at 2.5 A) for reliable switching in low-power crowbar and ignition circuits.

For engineers reviewing the X0202MA 2BL2 datasheet, X0202MA 2BL2 pinout, X0202MA 2BL2 application, or X0202MA 2BL2 equivalent, key selection criteria include gate sensitivity (200 µA max IGT), thermal resistance (Rth(j-l) = 60 °C/W), holding current (≤5 mA), and TO-92 mechanical compatibility in space-constrained protection designs.

Technical Context

This SCR operates in quadrant I (positive Anode-to-Cathode voltage, positive Gate-to-Cathode trigger) and latches after gate pulse removal. Its low IGT enables direct drive from microcontroller GPIOs or optocouplers without external amplification, while high dV/dt immunity (10–15 V/µs) prevents false triggering in noisy power supply environments.

Thermal design relies on junction-to-lead resistance (60 °C/W) and maximum junction temperature (125 °C), with derated IT(AV) of 0.8 A at TL = 63 °C. The device sustains non-repetitive surge currents up to 22.5 A (60 Hz, 10 ms) and fusing I²t of 2.5 A²s, supporting transient overvoltage clamping.

Key Specifications

Pinout & Package

Package: TO-92 - 3-lead through-hole plastic package with axial lead configuration, lead-free plating, UL94 V0 epoxy, and 0.2 g unit weight. Designed for manual soldering and wave soldering with standard PCB footprints.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SCR-based protection and switching applications.

Compared with MCR106-6 and S4006L, X0202MA 2BL2 offers balanced gate sensitivity (200 µA max), proven ruggedness in crowbar duty, and ST's long-term industrial support-making it optimal for cost-sensitive, high-volume protection modules where moderate IGT tolerance is acceptable.

Availability

X0202MA 2BL2 is available at Aetrix Electronics and suitable for ground fault interrupters, overvoltage crowbar circuits, and capacitive ignition systems requiring stable component supply, consistent TO-92 mechanical fit, and verified 600 V/1.25 A switching performance.

Supply support for X0202MA 2BL2 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, Switzerland, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The X02 series is ST's dedicated family of sensitive-gate SCRs engineered for low-power protection and timing-critical switching in harsh environments-emphasizing gate sensitivity, thermal robustness, and long-term reliability over high-current handling.

FAQ

What is the maximum gate-cathode voltage the X0202MA 2BL2 can withstand?

The absolute maximum gate-cathode reverse voltage (VRG) is not specified, but the gate-cathode forward voltage (VGT) is guaranteed ≤0.8 V at IGT test conditions. The gate-cathode leakage (IRG) is measured at 10 µA with ≥8 V applied, indicating safe forward bias operation up to 0.8 V and reverse bias tolerance exceeding typical logic levels. Exceeding ±5 V risks permanent gate damage.

Can the X0202MA 2BL2 be used in AC phase-control applications?

Yes-it supports quadrant I triggering and latching in AC line-synchronized circuits. However, its 1.25 A IT(RMS) and TO-92 thermal limits restrict use to loads ≤150 W at 230 VAC. For phase control, ensure gate drive is synchronized to zero-crossing and holding current (IH ≤5 mA) is maintained during each half-cycle to avoid unintended commutation.

How does the TO-92 package affect thermal performance compared to SOT-223 variants?

The TO-92 version has Rth(j-l) = 60 °C/W versus 25 °C/W for SOT-223, resulting in ~2.4× higher junction temperature rise at the same power dissipation. At 1.25 A RMS and VT ≈1.3 V, power loss is ~1.6 W-raising junction temperature ~96 °C above lead temperature. This necessitates conservative derating below 0.8 A average current in still-air environments.

Is the X0202MA 2BL2 compliant with RoHS and REACH regulations?

Yes-the TO-92 package uses lead-free plating and halogen-free molding compound, meeting RoHS Directive 2011/65/EU and REACH SVHC requirements. ST's ECOPACK® documentation confirms compliance, and the device carries the "ECOPACK2" marking per DS2122 Rev 7, page 6. Full material declarations are available via ST's product change notifications.