STMicroelectronics STX790A-AP

Overview

STX790A-AP from STMicroelectronics is a medium-current, high-performance, low-voltage PNP bipolar junction transistor in TO-92AP package, featuring V(BR)CER = −40 V, IC = −3 A continuous, VCE(sat) = −0.15 V (IC = −0.5 A, IB = −5 mA), hFE > 100, and TJ(max) = 150 °C; used as heavy-load switch in battery charger switching regulators.

For engineers reviewing the STX790A-AP datasheet, STX790A-AP pinout, STX790A-AP application, or STX790A-AP equivalent, key selection criteria include saturation voltage under high current, DC gain stability across collector current range, thermal resistance (Rthj-amb = 139 °C/W), and TO-92AP mechanical compatibility with automated insertion.

Technical Context

This PNP transistor employs "Base Island" planar technology to achieve simultaneous low VCE(sat) and high hFE-enabling efficient power switching at low voltage drop. Its RBE = 47 Ω test condition for V(BR)CER reflects built-in base-emitter resistor integration for enhanced ruggedness in inductive load switching.

Designed for operation up to 150 °C junction temperature, it delivers stable hFE ≥ 100 from IC = −10 mA to −2 A (VCE = −2 V), with VCE(sat) remaining ≤ −0.7 V even at IC = −3 A/IB = −100 mA-critical for minimizing conduction loss in portable power management circuits.

Key Specifications

Pinout & Package

Supplied in TO-92AP package (halogen-free molding compound), with standard three-terminal PNP configuration: Emitter (pin 1), Base (pin 2), Collector (pin 3), viewed from flat side with leads down.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP medium-current switching applications.

Compared with MJD2955T4G and BC807-40-7-F, STX790A-AP uniquely balances −3 A capability, −40 V ruggedness, and TO-92AP through-hole compatibility-making it optimal for cost-sensitive, thermally constrained portable power stages requiring no heatsink.

Availability

STX790A-AP is available at Aetrix Electronics and suitable for battery charger switching regulators, portable equipment power management, and voltage regulation in bias supply circuits requiring stable component supply and long-term obsolescence mitigation.

Supply support for STX790A-AP 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 for automotive, industrial, and consumer markets.

The STX790A belongs to ST's general-purpose bipolar transistor product line, engineered specifically for high-gain, low-saturation-voltage switching in space- and thermal-constrained portable power systems.

FAQ

What is the maximum safe operating collector current for STX790A-AP at 70 °C ambient?

At Tamb = 70 °C, derating applies: Ptot = 0.9 W × (1 − (70 − 25)/139) = 0.57 W. With VCE(sat) ≈ −0.5 V at −2 A, max continuous IC is −2.4 A. Exceeding this risks junction overheating beyond 150 °C, triggering thermal runaway.

Does STX790A-AP have integrated base-emitter resistor?

No. STX790A-AP is a discrete PNP transistor without internal base resistors. The V(BR)CER test condition (RBE = 47 Ω) refers to an external resistor used during characterization-not a built-in component. External base drive must include current-limiting resistor.

Is STX790A-AP suitable for linear regulator applications?

Yes, but only in emitter-follower configuration with light-to-moderate loads (< −1 A). Its low VCE(sat) and stable hFE support low-dropout bias regulation; however, power dissipation must stay within 0.57 W at 70 °C ambient to avoid exceeding TJ(max) = 150 °C.

How does the TO-92AP package differ mechanically from standard TO-92?

TO-92AP uses identical leadframe geometry but features ammopack tape-and-reel packaging optimized for automated insertion. Mechanical dimensions match TO-92 (A = 4.32–4.95 mm, D = 4.45–4.95 mm, L = 12.70–15.49 mm), with tighter tolerances on e1 (1.14–1.40 mm) and S1 (0.92–1.52 mm) to ensure pick-and-place reliability.