Diodes Incorporated FCX495TA

Overview

FCX495TA from Diodes Incorporated is a 150V NPN high-voltage transistor in SOT89 package, rated for 1A continuous collector current and featuring V_CE(sat) < 300 mV at 0.5A. It delivers robust switching performance in low-loss power conversion stages, with BV_CEO = 150 V, h_FE = 100–300 (IC = 1mA to 1A), and R_θJL = 10.01 °C/W for efficient thermal transfer via the exposed collector pad.

For engineers reviewing the FCX495TA datasheet, FCX495TA pinout, FCX495TA application, or FCX495TA equivalent, key selection criteria include high-voltage blocking capability (150 V V_CEO), low saturation voltage under medium load (≤300 mV @ 0.5A), thermal performance on FR4 PCBs, and compatibility with automotive-grade variants (FCX495Q) where AEC-Q101 compliance is required.

Technical Context

This NPN bipolar junction transistor operates as a medium-power, high-voltage switch with fixed gain architecture-no integrated biasing or protection circuitry. Its safe operating area (SOA) is defined up to 150 V and 1 A DC, with pulse capability extending to 2 A for short durations (≤100 µs).

Thermal design relies on direct conduction from the die to the exposed collector lead (R_θJL = 10.01 °C/W), making PCB copper layout critical. The device exhibits f_T = 100 MHz at IC = 50 mA, supporting moderate-frequency switching but not RF or high-speed digital applications.

Key Specifications

Pinout & Package

FCX495TA is housed in a surface-mount SOT89 package with an exposed collector pad for thermal management. The plastic body meets UL 94V-0 flammability rating and uses halogen/antimony-free "Green" molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX653 and MJD122, FCX495TA uniquely balances 150 V blocking, 1 A current, and low thermal resistance via its exposed-collector SOT89 construction-making it optimal for space-constrained, medium-voltage switching where thermal efficiency is critical.

Availability

FCX495TA is available at Aetrix Electronics and suitable for LED drivers, offline auxiliary supplies, industrial relay interfaces, and low-power DC motor control requiring stable component supply and long-term manufacturability.

Supply support for FCX495TA 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 distribution operations across Asia, Europe, and North America.

The FCX495TA belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for reliable, thermally efficient switching in cost-sensitive industrial and lighting applications where 100–150 V breakdown and SMT assembly are required.

FAQ

What is the maximum allowable continuous collector current for FCX495TA at 70°C ambient?

At T_A = 70°C, the derated continuous collector current is 0.6 A. This is calculated using the 1 W power dissipation limit and the 125 °C/W R_θJA value: P_D = (T_J(max) − T_A) / R_θJA = (150 − 70) / 125 = 0.64 W, and I_C = √(P_D / R_CE(sat)) ≈ 0.6 A assuming typical V_CE(sat) of 250 mV.

Does FCX495TA include built-in base-emitter resistors or protection features?

No. FCX495TA is a bare NPN transistor with no integrated base resistors, ESD protection diodes, or clamp structures. External components-including base current limiting resistors and collector flyback diodes for inductive loads-are required per application circuit requirements.

Can FCX495TA be used in automotive applications?

The FCX495TA is not AEC-Q101 qualified. However, Diodes offers the FCX495Q variant-a functionally identical part tested and certified to AEC-Q101 standards for automotive under-hood and infotainment systems requiring extended temperature and reliability validation.

What is the recommended PCB pad layout for optimal thermal performance?

Per Diodes' package outline, the collector pad should connect to ≥15 mm × 15 mm single-sided 1 oz copper on FR4. Recommended pad dimensions match the SOT89 footprint: 4.5 mm × 2.5 mm for the main pad, with thermal vias (≥4 × 0.3 mm) connecting to inner-layer or backside copper planes to achieve R_θJA ≤ 125 °C/W in still air.