STMicroelectronics X0202NN 5BA4

Overview

X0202NN 5BA4 from STMicroelectronics is a sensitive-gate silicon-controlled rectifier (SCR) rated for 1.25 A RMS on-state current and 800 V repetitive peak off-state voltage (VDRM/VRRM), with gate trigger current (IGT) of 50–200 µA. It operates in SOT-223 package, optimized for low forward voltage drop (max 1.45 V at 2.5 A) and high inrush current tolerance (25 A surge), enabling reliable crowbar protection and capacitive ignition in compact power systems.

For engineers reviewing the X0202NN 5BA4 datasheet, X0202NN 5BA4 pinout, X0202NN 5BA4 application, or X0202NN 5BA4 equivalent, key selection criteria include its 800 V blocking capability, sub-200 µA gate sensitivity, thermal resistance (Rth(j-t) = 25 °C/W), and SOT-223 footprint compatibility with space-constrained PCB layouts in safety-critical AC control circuits.

Technical Context

This SCR uses planar passivated junction technology to achieve stable dV/dt immunity (min 15 V/µs at 110 °C) and robust latching behavior (IL ≤ 6 mA). Its low dynamic resistance (Rd ≤ 200 mΩ) and threshold voltage (VTO ≤ 0.9 V at 125 °C) minimize conduction losses during sustained on-state operation.

The device supports bidirectional triggering (both polarities of A2 referenced to A1) and features guaranteed IGT minimum at 5% of max rating. Thermal design is enabled by validated junction-to-tab resistance (25 °C/W) and defined derating curves for RMS current versus tab temperature in SOT-223 mounting configurations.

Key Specifications

Pinout & Package

Package: SOT-223 (3-lead, surface-mount, tab-connected to cathode). Thermal pad enables direct heatsinking via PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STX0202NA 1BA2 and S4006L, X0202NN 5BA4 uniquely balances ultra-low gate sensitivity, 800 V blocking, and SOT-223 thermal efficiency-making it optimal for automated, space-constrained crowbar designs where gate drive headroom and PCB real estate are limited.

Availability

X0202NN 5BA4 is available at Aetrix Electronics and suitable for ground fault interruption, overvoltage crowbar protection, and capacitive ignition circuits requiring stable component supply, consistent parametric performance, and RoHS-compliant packaging.

Supply support for X0202NN 5BA4 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, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The X02 series is part of ST's high-reliability discrete power portfolio, engineered specifically for ruggedized AC control, safety-critical protection, and compact ignition systems operating across -40 to +125 °C ambient ranges.

FAQ

What is the maximum junction temperature for continuous operation?

The X0202NN 5BA4 has a specified operating junction temperature range of -40 to +125 °C. Continuous operation at 125 °C requires strict adherence to derated IT(RMS) limits per Figure 2 in DS2122 Rev 7, where SOT-223 tab temperature must not exceed 99 °C under full 1.25 A load.

Can this SCR be triggered with a microcontroller GPIO pin directly?

Yes-its IGT range of 50–200 µA allows direct triggering from most 3.3 V or 5 V microcontroller GPIO pins when used with a current-limiting resistor (e.g., 22 kΩ for ~150 µA at 3.3 V), provided the GPIO can sink ≥1 mA and the gate-cathode capacitance is minimized to avoid false triggering.

Does the SOT-223 package require thermal vias for 1.25 A operation?

Yes-DS2122 specifies Rth(j-t) = 25 °C/W assuming the tab is soldered to ≥5 cm² of 2-oz copper. For 1.25 A RMS at ambient >60 °C, at least six 0.3 mm diameter thermal vias under the tab are recommended to maintain junction temperature below 125 °C per thermal simulation guidelines in ST AN4143.

How does dV/dt immunity change with gate-cathode resistance?

Figure 7 in DS2122 shows dV/dt immunity increases with higher RGK values-e.g., at RGK = 1 kΩ, dV/dt ≥15 V/µs at 110 °C, but rises to ~25 V/µs at RGK = 10 kΩ. However, excessive RGK delays turn-on and may cause misfiring; 1 kΩ is the standard test condition and recommended design value.