STMicroelectronics P0111DA 5AL3

Overview

P0111DA 5AL3 from STMicroelectronics is a sensitive gate silicon-controlled rectifier (SCR) rated for 400 V repetitive peak off-state voltage (VDRM/VRRM), 0.8 A RMS on-state current (IT(RMS)), and ultra-low gate trigger current (IGT) of 4–25 µA. It operates in TO-92 package and is engineered for low-power, high-immunity switching in safety-critical pilot circuits-specifically ground fault circuit interruptors (GFCIs), solid-state relay control stages, standby power supplies, and smoke/CO alarm detectors.

For engineers reviewing the P0111DA 5AL3 datasheet, P0111DA 5AL3 pinout, P0111DA 5AL3 application, or P0111DA 5AL3 equivalent, this device delivers verified low-IGT triggering, robust dV/dt immunity (≥80 V/µs at Tj = 125 °C), and thermal stability up to 125 °C junction temperature-critical for space-constrained, low-current gate drive designs requiring fail-safe latching behavior.

Technical Context

This SCR uses planar passivated silicon technology with optimized gate sensitivity to enable reliable turn-on under sub-10 µA gate drive conditions. Its holding current (IH ≤ 5 mA) and latching current (IL ≤ 6 mA) are tightly specified across –40 to +125 °C, ensuring stable conduction after triggering without external gate sustain.

The device features a dynamic resistance (Rd ≤ 600 mΩ) and threshold voltage (Vt0 ≤ 0.95 V at Tj = 125 °C), enabling low conduction loss at rated IT(AV) = 0.5 A. Its critical dI/dt rating (50 A/µs) and surge capability (ITSM = 8 A, tp = 8.3 ms) support transient-resistant operation in inductive load switching.

Key Specifications

Pinout & Package

Package: TO-92 (plastic, epoxy UL94 V0 compliant), 3-terminal through-hole package with standard lead spacing and mechanical dimensions per Table 5 (A = 1.35 mm, E = 12.70 mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar sensitive-gate SCR applications.

Compared with BT169G and TYN104, P0111DA 5AL3 provides the narrowest IGT range (4–25 µA), lowest thermal resistance in TO-92, and highest dV/dt immunity-making it uniquely suited for battery-operated, space-constrained, and noise-prone safety sensing applications where gate drive headroom is minimal.

Availability

P0111DA 5AL3 is available at Aetrix Electronics and suitable for ground fault circuit interruptors, solid-state relay pilot circuits, and standby power supply enable functions requiring stable component supply, long-term lifecycle continuity, and RoHS-compliant packaging.

Supply support for P0111DA 5AL3 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, discrete devices, and MEMS sensors for industrial, automotive, and consumer markets.

The P011xx series belongs to ST's high-immunity SCR product line, developed specifically for safety-critical, low-power AC control applications where gate drive current is severely constrained and false triggering must be avoided.

FAQ

What is the maximum junction temperature and how does it affect reliability?

The P0111DA 5AL3 has a maximum operating junction temperature (Tj) of +125 °C. Its electrical parameters-including IGT, IH, and dV/dt-are fully characterized up to this limit, and thermal derating curves (Fig. 3) confirm usable IT(AV) down to 0.3 A at 70 °C ambient with standard TO-92 mounting. Exceeding Tj = 125 °C risks parametric shift and accelerated wear-out.

Can this SCR be driven directly from a 3.3 V microcontroller GPIO?

Yes-provided the GPIO can source ≥25 µA (max IGT) into a ≤1 kΩ gate-cathode resistor. At 3.3 V, a 130 kΩ pull-up yields ~25 µA, satisfying worst-case IGT. However, layout must minimize gate loop inductance and avoid routing near noisy traces to preserve dV/dt immunity.

How does the 80 V/µs dV/dt rating translate to real-world noise immunity?

A dV/dt of 80 V/µs means the device withstands voltage transients rising faster than 80 V per microsecond without false turn-on. In 50 Hz AC systems, this corresponds to immunity against typical switching spikes (<1 µs rise time) from relays or triacs, provided RGK ≤ 1 kΩ and layout avoids floating gate nodes.

Is the TO-92 package lead-free and RoHS compliant?

Yes-the P0111DA 5AL3 is supplied in ST's ECOPACK®-compliant TO-92 package, meeting RoHS Directive 2011/65/EU and halogen-free requirements. The "5AL3" packing code denotes tape-and-reel delivery with lead-free, matte-tin-plated leads and UL94 V0 epoxy encapsulation.