STMicroelectronics 2SB772

Overview

2SB772 from STMicroelectronics is a PNP medium-power bipolar junction transistor (BJT) designed for switching and linear amplification roles in power control circuits. It delivers −3 A continuous collector current, −30 V V_CEO, 12.5 W total dissipation at T_C = 25°C, and low saturation voltage (V_CE(sat) = −0.4 V @ I_C = −1 A, I_B = −50 mA), enabling efficient operation in relay drivers and audio power stages.

For engineers reviewing the 2SB772 datasheet, 2SB772 pinout, 2SB772 application, or 2SB772 equivalent, key selection criteria include verified PNP polarity, TO-126 (SOT-32) package thermal performance, DC current gain (h_FE = 100–300), safe operating area under pulsed loads, and complementary pairing with 2SD882 in push-pull configurations.

Technical Context

This device uses planar epitaxial technology to achieve ruggedness and stable high-current operation. Its −30 V V_CEO and −60 V V_CBO support use in 24 V industrial supply rails and DC-DC converter output stages where reverse-biased breakdown margin is critical.

The transistor exhibits h_FE = 80 min @ I_C = −1 A and f_T = 100 MHz, confirming suitability for audio-frequency amplification and fast-switching applications up to several hundred kHz, with V_BE(sat) = −1.2 V @ I_C = −2 A ensuring predictable base drive requirements.

Key Specifications

Pinout & Package

Package: SOT-32 (TO-126) - three-terminal plastic power package with metal tab for heatsink mounting and thermal path optimization.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP medium-power transistor applications.

Compared with MJD2955 and BC557B, the 2SB772 uniquely balances −3 A current, −30 V rating, TO-126 thermal performance, and audio-grade h_FE linearity-making it optimal for cost-sensitive industrial relay drivers and mid-power analog amplifiers where package size and thermal interface matter.

Availability

2SB772 is available at Aetrix Electronics and suitable for voltage regulation, relay driver, and audio power amplifier applications requiring stable component supply across industrial control, building automation, and legacy audio equipment manufacturing.

Supply support for 2SB772 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, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The 2SB772 belongs to ST's legacy bipolar power transistor family, engineered specifically for robust, cost-effective switching and linear amplification in industrial power interfaces and analog signal chains.

FAQ

Is the 2SB772 RoHS-compliant and lead-free?

Yes. The 2SB772 is manufactured in ECOPACK®-compliant SOT-32 packages with lead-free second-level interconnects, meeting JEDEC JESD97 standards. The inner box label indicates the lead-free category, and soldering profiles follow ST's specified thermal limits for Pb-free reflow.

Can the 2SB772 replace the 2N2907 in existing designs?

No. While both are PNP transistors, the 2SB772 has −3 A I_C and 12.5 W dissipation versus 2N2907's −600 mA and 400 mW. Substituting without circuit review risks thermal runaway, excessive base drive demand, and package incompatibility (TO-126 vs TO-18).

What is the safe operating area (SOA) limitation at 100°C case temperature?

At T_C = 100°C, the maximum allowable collector current drops to approximately −1.8 A for DC operation due to thermal derating. Pulse operation (t_P < 5 ms) extends peak current to −4.2 A, as defined by the reverse-biased SOA curve in Figure 2 of the datasheet.

Does the 2SB772 require a heatsink in typical relay driver use?

Yes, for continuous operation above ~500 mA collector current or duty cycles >30%, a heatsink is recommended. With R_thJ-case = 10 °C/W, even 2 W dissipation raises junction temperature by 20°C above case-exceeding safe margins without thermal management.