Diodes Incorporated FCX619QTA

Overview

FCX619QTA from Diodes Incorporated is a 50V NPN low-saturation power transistor in SOT89 package, rated for 3A continuous collector current and 6A peak pulse current, with V_CE(sat) < 220mV at 1A and R_CE(sat) = 87mΩ at 2.75A, used in automotive-grade load management and motor control circuits.

For engineers reviewing the FCX619QTA datasheet, FCX619QTA pinout, FCX619QTA application, or FCX619QTA equivalent, key selection criteria include AEC-Q101 qualification, thermal resistance (R_θJA = 62.5°C/W on 40mm×40mm 1oz copper), h_FE characterization up to 6A, and low 87mΩ on-resistance at high current.

Technical Context

This NPN power transistor operates as a high-current switching element with robust breakdown ratings: V_CBO ≥ 50V, V_CEO ≥ 50V, and V_EBO ≥ 7V. Its low saturation voltage enables efficient conduction in DC-DC converters and motor drivers where power loss minimization is critical.

Thermal performance is defined across four mounting conditions - from 178°C/W on minimal pad layout to 62.5°C/W on 40mm×40mm copper - and it delivers f_T = 100–165MHz, supporting fast-switching applications while maintaining stable h_FE up to 6A.

Key Specifications

Pinout & Package

FCX619QTA uses the SOT89 surface-mount package with an exposed collector pad for enhanced thermal dissipation. The molded plastic case meets UL 94V-0 flammability rating and JEDEC moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN power transistor applications.

Compared with ZXTN2012ZTA and MJD122G, FCX619QTA uniquely balances AEC-Q101 compliance, 3A continuous rating, 87mΩ on-resistance, and SOT89 thermal efficiency - making it optimal for space-constrained automotive power switches where both reliability and conduction loss matter.

Availability

FCX619QTA is available at Aetrix Electronics and suitable for automotive load management, brushed DC motor control, and DC-DC converter output stages requiring stable component supply and AEC-Q101 traceability.

Supply support for FCX619QTA 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, specializing in high-reliability components for automotive, industrial, and computing markets.

The FCX619QTA belongs to Diodes' AEC-Q101-qualified power transistor product line, engineered specifically for robust switching in automotive body electronics and power management systems where thermal stability and long-term reliability are critical.

FAQ

What is the maximum allowable junction temperature for FCX619QTA?

The FCX619QTA has a specified operating junction temperature range of −55°C to +150°C. This rating is validated under AEC-Q101 stress testing and applies across all automotive ambient conditions when mounted per recommended pad layout. Thermal derating curves in the datasheet define power limits above +25°C ambient.

Is FCX619QTA pin-compatible with FCX619TA or FCX619-13R?

Yes - FCX619QTA, FCX619TA, and FCX619-13R share identical SOT89 pinout (C-E-B), electrical specifications, and thermal characteristics. The only differences are packaging (reel size/tape width) and compliance marking: FCX619QTA carries "Automotive" marking and is PPAP-capable, while FCX619TA is marked "AEC-Q101".

Does FCX619QTA require a heatsink in typical automotive applications?

No external heatsink is required if the exposed collector pad is soldered to ≥40mm×40mm of 1oz copper, achieving R_θJA = 62.5°C/W. At 3A continuous current and 25°C ambient, junction temperature rise is ~117°C - within the 150°C limit. Smaller copper areas necessitate derating or airflow.

How does the hFE characterization up to 6A benefit circuit design?

h_FE data at 6A enables precise base current calculation for peak-load conditions like motor stall or inrush, avoiding overdesign of drive circuitry. Unlike transistors with h_FE only specified at 10–100mA, FCX619QTA's full-range gain curve ensures predictable saturation behavior across its entire operational envelope.