STMicroelectronics 2STA2120

Overview

2STA2120 from STMicroelectronics is a high-power PNP epitaxial planar bipolar transistor designed for linear audio power amplification, featuring V_CEO = −250 V, I_C = −17 A, P_TOT = 200 W at T_C = 25 °C, f_T = 25 MHz, and R_thj-case = 0.625 °C/W - deployed in high-fidelity discrete output stages of Class AB audio amplifiers.

For engineers reviewing the 2STA2120 datasheet, 2STA2120 pinout, 2STA2120 application, or 2STA2120 equivalent, key selection considerations include safe operating area (SOA) at elevated case temperatures, gain linearity under large-signal swing, complementary pairing with 2STC5948, and thermal derating above 25 °C.

Technical Context

This PNP transistor employs ST's BiT-LA (Bipolar transistor for linear amplifier) process to optimize h_FE linearity and minimize distortion across collector current ranges from −1 A to −7 A. Its breakdown ratings (V_CBO = V_CEO = −250 V) and rugged SOA support high-voltage rail operation in discrete push-pull output stages.

The device is fully characterized up to T_J = 150 °C and T_C = 125 °C, with specified V_CE(sat) = −3 V at I_C = −8 A / I_B = −800 mA and h_FE = 35–160 (min/typ/max) at I_C = −7 A, enabling predictable biasing and thermal stability in high-power analog designs.

Key Specifications

Pinout & Package

Supplied in TO-3P (also known as TO-218) package: metal tab (collector), pin 1 (base), pin 2 (emitter), pin 3 (collector tab electrically connected - dual collector connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJE15031 and BDW93C, the 2STA2120 delivers superior power handling (200 W vs. ≤150 W), higher f_T (25 MHz vs. ≤3 MHz), and tighter thermal resistance - making it uniquely suited for high-fidelity, high-rail audio and precision linear regulation where SOA, linearity, and bandwidth are jointly critical.

Availability

2STA2120 is available at Aetrix Electronics and suitable for high-fidelity audio amplifiers, professional PA systems, and industrial linear regulator designs requiring stable component supply and long-term manufacturability assurance.

Supply support for 2STA2120 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 power devices for industrial, automotive, and consumer markets.

The 2STA2120 belongs to ST's high-voltage linear bipolar transistor family, engineered specifically for low-distortion, high-reliability audio and power linear applications using the BiT-LA process.

FAQ

Is the 2STA2120 still in active production?

No - STMicroelectronics has marked the 2STA2120 as Obsolete Product(s) per its official datasheet revision history (Rev 3, Nov 2008). However, Aetrix Electronics maintains legacy inventory with full traceability and offers extended supply support including last-time buy coordination and cross-reference guidance for functional replacements.

What is the correct pinout orientation for TO-3P package mounting?

When viewing the TO-3P package with leads facing downward and the tab oriented toward the viewer, pin 1 (base) is leftmost, pin 2 (emitter) is center, and pin 3 (collector) is rightmost - with the metal tab also serving as collector. Mounting requires electrically isolating the tab unless circuit topology grounds the collector.

Can the 2STA2120 be used in parallel configurations?

Yes - but only with emitter ballast resistors (typically 0.1–0.22 Ω) and matched devices (h_FE and V_BE within 10%). The BiT-LA process improves unit-to-unit parameter uniformity, yet thermal coupling and current sharing must be verified via SOA-limited testing at maximum case temperature.

Does the 2STA2120 require a minimum base drive current for linear operation?

Yes - for linear amplification at I_C = −7 A, typical V_BE = −1.5 V and h_FE ≥ 35 imply ≥200 mA base current. At saturation (I_C = −8 A), I_B ≥ −800 mA is required to maintain V_CE(sat) ≤ −3 V; insufficient drive causes localized heating and SOA violation.