STMicroelectronics 2STR1215

Overview

2STR1215 from STMicroelectronics is a low-voltage, fast-switching NPN power transistor fabricated with PB-HCD (Power Bipolar High Current Density) technology, delivering V_CE(sat) = 0.15 V at I_C = 0.1 A / I_B = 1 mA, h_FE ≥ 200 at I_C = 50 mA, and t_off = 310 ns in resistive-load switching - used in LED driver stages and battery charger current-control paths.

For engineers reviewing the 2STR1215 datasheet, 2STR1215 pinout, 2STR1215 application, or 2STR1215 equivalent, this device supports high-gain, low-saturation switching in space-constrained SOT-23 surface-mount designs where thermal resistance (R_thj-amb = 250 °C/W on 1 cm² PCB) and fast turn-off timing are critical for efficiency.

Technical Context

The 2STR1215 operates as a single NPN bipolar junction transistor optimized for low-voltage DC switching (V_CEO = 15 V, V_CB0 = 15 V), with guaranteed saturation voltage ≤ 0.25 V at I_C = 1 A / I_B = 100 mA and DC current gain spanning 130–560 across 50 mA–2 A collector currents.

Its fast switching performance (t_on = 60 ns, t_off = 310 ns) is validated under pulsed resistive-load conditions (V_CC = 10 V, I_C = 1.5 A), and it uses an ECOPACK®-compliant SOT-23 package with lead-free second-level interconnect per JEDEC JESD97.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package with standard 3-pin configuration: emitter (pin 1), base (pin 2), collector (pin 3), compliant with ECOPACK® environmental requirements and JEDEC JESD97 marking standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT2222A and ZTX653, the 2STR1215 uniquely balances ultra-low V_CE(sat), fast t_off, and SOT-23 compactness - making it optimal for high-efficiency, space-constrained 1 A switching where thermal budget and PWM fidelity are critical.

Availability

2STR1215 is available at Aetrix Electronics and suitable for LED driver stages, battery charger control circuits, and voltage regulation modules requiring stable component supply and consistent parametric performance across production batches.

Supply support for 2STR1215 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 and discrete devices for industrial, automotive, and consumer markets.

The 2STR1215 belongs to ST's low-voltage power transistor family developed specifically for high-efficiency, surface-mount switching in portable and space-constrained power management systems.

FAQ

What is the maximum continuous collector current for the 2STR1215?

The 2STR1215 has a rated continuous collector current (I_C) of 1.5 A at T_amb = 25 °C with adequate PCB copper area (1 cm²). Derating applies above 25 °C ambient - at 85 °C, maximum usable I_C drops to approximately 0.75 A based on its 250 °C/W thermal resistance and 0.5 W total power dissipation limit.

Can the 2STR1215 replace a general-purpose NPN like BC817 in a 500 mA load?

Yes - the 2STR1215 offers superior performance: h_FE ≥ 200 (vs. BC817's 160–630, but typically lower at high I_C) and V_CE(sat) = 0.15 V @ 0.1 A (vs. BC817's 0.2 V min), with faster switching. Its SOT-23 footprint is pin-compatible with BC817-40 variants, enabling direct upgrade in existing layouts without redesign.

Is the 2STR1215 suitable for PWM switching at 1 MHz?

No - while t_off = 310 ns suggests theoretical capability, the device's 16 pF C_CBO and finite h_FE roll-off above 100 kHz limit practical use to ≤500 kHz. At 1 MHz, switching losses increase significantly and gain drops below usable levels; a MOSFET or RF-optimized transistor is recommended instead.

Does the 2STR1215 require a base resistor in typical switching applications?

Yes - a base resistor is mandatory to limit I_B and ensure proper saturation. For 1 A I_C, minimum I_B = 1 A / h_FE(min) ≈ 5 mA (using h_FE = 200), so with 3.3 V GPIO drive and V_BE(sat) ≈ 1.0 V, R_B ≈ (3.3 − 1.0) V / 5 mA = 460 Ω. A 470 Ω standard value ensures robust saturation without overdriving.