Diodes Incorporated FCX591TA

Overview

FCX591TA from Diodes Incorporated is a 60V PNP medium-power transistor in SOT89 package, rated for -1A continuous collector current, -60V V_CEO, and 295mΩ R_CE(SAT) at -1A/-100mA drive, used in automotive load switching and industrial DC-DC converter output stages.

For engineers reviewing the FCX591TA datasheet, FCX591TA pinout, FCX591TA application, or FCX591TA equivalent, key selection criteria include verified V_CEO ≥ -60V, h_FE ≥ 100 at -1A, R_CE(SAT) ≤ 300mΩ, thermal resistance R_θJC = 16°C/W, and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This PNP bipolar junction transistor operates with emitter-grounded configuration and supports high-current linear and saturated switching modes. Its h_FE is characterized up to -2A, maintaining ≥40 at full rated I_C, and exhibits f_T = 150MHz for moderate-frequency control applications.

The device features low R_CE(SAT) (295mΩ typical at -1A/-100mA) enabled by optimized base drive and epitaxial structure, and integrates an exposed collector pad for direct thermal conduction to PCB copper, yielding R_θJC = 16°C/W and R_θJL = 22°C/W.

Key Specifications

Pinout & Package

Package: SOT89 - surface-mount plastic case with exposed collector pad for thermal dissipation; dimensions per AP02002 (4.5mm × 2.45mm × 1.5mm), weight ≈ 0.05g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX653 and MJD2955T4G, FCX591TA uniquely combines AEC-Q101 qualification, SOT89 form factor, and lowest R_CE(SAT) among PNP transistors rated for -1A in this package, making it optimal for thermally constrained automotive and industrial switching.

Availability

FCX591TA is available at Aetrix Electronics and suitable for automotive body control modules, industrial 24V DC-DC converters, and commercial LED driver designs requiring stable component supply across production lifecycles.

Supply support for FCX591TA 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The FCX591TA belongs to Diodes' FCX series of medium-power bipolar transistors engineered for automotive and industrial switching applications demanding AEC-Q101 reliability, low saturation voltage, and SOT89 thermal efficiency.

FAQ

What is the maximum continuous collector current for FCX591TA at 100°C ambient temperature?

At T_A = 100°C, FCX591TA's maximum continuous collector current is derated to approximately -600mA, based on its 1W power dissipation limit and R_θJA = 125°C/W (15mm×15mm copper). Full -1A rating applies only up to T_A = 25°C with proper PCB thermal design.

Does FCX591TA support pulsed operation beyond its continuous ratings?

Yes - FCX591TA supports I_CM = -2A peak collector current under pulsed conditions (pulse width ≤ 300µs, duty cycle ≤ 2%), as confirmed in the absolute maximum ratings table and electrical characteristics notes.

How is the exposed collector pad on the SOT89 package intended to be used thermally?

The exposed collector pad must be soldered directly to ≥15mm² of 1oz copper on the PCB to achieve the specified R_θJC = 16°C/W and full 1W power dissipation. Thermal vias beneath the pad are recommended to enhance heat transfer to internal layers.

Is FCX591TA pin-compatible with its complementary NPN counterpart FCX491?

No - FCX591TA (PNP) and FCX491 (NPN) share the same SOT89 package and pinout order (C-E-B), but their polarity and biasing requirements differ fundamentally; they are functionally complementary, not drop-in replacements.