STMicroelectronics P0118MA 5AL3

Overview

P0118MA 5AL3 from STMicroelectronics is a sensitive high-immunity silicon-controlled rectifier (SCR) in TO-92 package, rated for 600 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 0.5–5 µA. It enables reliable latching in low-power pilot circuits where gate drive is severely constrained, such as ground fault circuit interrupters (GFCIs) and smoke detector standby power control.

For engineers reviewing the P0118MA 5AL3 datasheet, P0118MA 5AL3 pinout, P0118MA 5AL3 application, or P0118MA 5AL3 equivalent, this device is selected for ultra-low IGT sensitivity, 600 V blocking capability, TO-92 thermal performance, and robust dV/dt immunity in safety-critical AC line sensing and interruption circuits.

Technical Context

This SCR operates with a threshold voltage (Vt0) ≤ 0.95 V and dynamic resistance (Rd) ≤ 600 mΩ at Tj = 125 °C, enabling low conduction loss under limited gate drive. Its critical rate of rise of on-state current (dI/dt) is rated at 50 A/µs with IG = 2×IGT, supporting fast turn-on in transient-prone AC mains interfaces.

With holding current (IH) ≤ 5 mA and latching current (IL) ≤ 6 mA at RGK = 1 kΩ, it sustains conduction after triggering even with minimal gate-cathode leakage paths. Its dV/dt immunity exceeds 75 V/µs at Tj = 125 °C and RGK = 1 kΩ, ensuring noise immunity in high-impedance gate configurations typical of GFCI and alarm detector designs.

Key Specifications

Pinout & Package

Package: TO-92 (ECOPACK® compliant, UL94 V0 epoxy). Three-terminal through-hole package with standard A-K-G lead configuration (Anode–Cathode–Gate).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BT169G and TYN606, P0118MA 5AL3 uniquely delivers 600 V blocking with sub-1 µA gate sensitivity in TO-92-enabling miniaturized, ultra-low-power AC control where alternative SCRs require either voltage or current trade-offs.

Availability

P0118MA 5AL3 is available at Aetrix Electronics and suitable for ground fault detection, smoke alarm power management, solid-state relay pilot stages, and standby-mode AC enable circuits requiring stable component supply across long-lifecycle industrial and consumer programs.

Supply support for P0118MA 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, MCU, power, and discrete devices for industrial, automotive, and consumer markets.

P0118MA 5AL3 belongs to the P011xx sensitive SCR family, engineered specifically for ultra-low-gate-drive AC line control in safety-critical, space-constrained applications like GFCIs and life-safety detectors.

FAQ

What is the maximum junction temperature for continuous operation?

The P0118MA 5AL3 has an operating junction temperature range of –40 °C to +125 °C. For continuous IT(RMS) = 0.8 A operation in TO-92, ambient temperature must be limited to ≤70 °C with ≥5 cm² copper pad per Figure 4; derating is required above this ambient due to Rth(j-a) = 150 °C/W.

Can this SCR be used with zero-crossing detection circuits?

Yes - its dV/dt immunity ≥75 V/µs at 125 °C and low IGT allow integration into zero-crossing-triggered AC switches. Gate must be driven synchronously near voltage zero; external RC timing network or optocoupler with zero-crossing output is recommended to ensure precise phase alignment and avoid false triggering.

Is a snubber circuit required for reliable operation?

A snubber is not mandatory due to high intrinsic dV/dt immunity, but recommended for inductive loads or long trace runs. A 100 Ω resistor in series with 100 nF capacitor across A–K suppresses ringing and improves noise margin, especially when driving transformers or solenoids where di/dt-induced voltage spikes exceed 75 V/µs.

How does gate-cathode resistance affect triggering reliability?

RGK directly impacts IGT and dV/dt immunity: lower RGK (e.g., 1 kΩ) reduces effective IGT but degrades dV/dt rejection; higher RGK (>10 kΩ) increases noise immunity but raises required IGT. For P0118MA 5AL3, RGK = 1 kΩ is specified in all electrical tests and provides optimal balance between sensitivity and robustness in GFCI and alarm applications.