Diodes Incorporated FCX555TA

Overview

FCX555TA from Diodes Incorporated is a PNP high-voltage switching transistor in SOT89 package, rated for -150V V_CEO, -700mA continuous collector current, and V_CE(sat) < -300mV at -100mA. It serves as a robust high-side switch in industrial power supplies, relay drivers, and LED ballasts where high breakdown voltage and low saturation loss are critical.

For engineers reviewing the FCX555TA datasheet, FCX555TA pinout, FCX555TA application, or FCX555TA equivalent, key selection criteria include verified -150V V_CEO, thermal resistance of 60°C/W on 50mm × 50mm copper, AEC-Q101 qualification, and complementary pairing with FCX495 for push-pull topologies.

Technical Context

This PNP bipolar junction transistor operates in linear or saturated switching mode, with guaranteed BV_CEO ≥ -150V and BV_CEV ≥ -180V under pulsed and sustained conditions. Its h_FE ranges from 100 to 300 at IC = -10mA and -100mA, supporting stable DC gain across load currents.

The device features an exposed collector pad for enhanced thermal conduction, achieving R_ΘJL = 10.01°C/W to the solder point. ESD robustness includes ≥4,000V HBM per JEDEC JESD22-A114, enabling reliable handling in automated assembly lines.

Key Specifications

Pinout & Package

Package: SOT89 - surface-mount plastic package with exposed collector pad for thermal dissipation; dimensions per AP02002 (4.4–4.6 mm length, 2.29–2.60 mm width, 1.40–1.60 mm height).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX951 and MJD2955T4G, FCX555TA uniquely balances -150V rating, SOT89 footprint, AEC-Q101 compliance, and low V_CE(sat)-making it optimal for compact, automotive-qualified, medium-voltage switching where thermal management relies on PCB copper rather than discrete heatsinks.

Availability

FCX555TA is available at Aetrix Electronics and suitable for industrial power supplies, automotive relay drivers, LED ballasts, and programmable current sinks requiring stable component supply with long-term lifecycle assurance.

Supply support for FCX555TA 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 and manufacturing operations across Asia and the Americas.

The FCX555TA belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for ruggedized switching in automotive, industrial, and lighting applications demanding AEC-Q101 reliability and high-voltage tolerance.

FAQ

What is the maximum operating temperature for FCX555TA?

The FCX555TA has an operating junction temperature range of -65°C to +150°C. Its absolute maximum storage temperature matches this range. Derating begins above +25°C ambient, with maximum power dissipation dropping to zero at +150°C ambient when mounted on 50mm × 50mm copper, per the datasheet's thermal curve.

Is FCX555TA pin-compatible with FCX495?

No-FCX555TA (PNP) and FCX495 (NPN) are complementary devices but have opposite polarity and different pinouts. FCX555TA uses E-B-C order in SOT89, while FCX495 uses C-B-E. They are intended for matched pair designs-not drop-in replacements-and require separate PCB layout consideration.

Does FCX555TA require a heatsink in typical applications?

Not typically-the SOT89 package with exposed collector pad achieves R_ΘJA = 60°C/W on 50mm × 50mm copper, allowing 1W dissipation at +75°C ambient without a heatsink. Heatsinking is only needed if power exceeds 1W or PCB copper area is reduced below 25mm × 25mm.

Can FCX555TA be used in linear amplifier configurations?

Yes-it supports linear operation with h_FE specified from -10mA to -100mA and f_T = 100MHz at -50mA. However, its primary design intent is switching; linear use requires careful thermal design due to limited SOA at high V_CE/I_C combinations, as shown in the Safe Operating Area graph on page 5 of DS33058.