Diodes Incorporated FZT493TC

Overview

FZT493TC from Diodes Incorporated is a 100V NPN medium-power transistor in SOT223 package, rated for 1A continuous collector current and 2A peak pulse current, with V_CE(sat) ≤ 0.6V at I_C = 1A/I_B = 100mA, and qualified to AEC-Q101 for automotive reliability. It serves as a high-voltage switching element in DC-DC converters, motor drivers, and LED lighting ballasts.

For engineers reviewing the FZT493TC datasheet, FZT493TC pinout, FZT493TC application, or FZT493TC equivalent, key selection criteria include breakdown voltage (V_CEO = 100V), thermal resistance (R_θJA = 41.7°C/W on 50mm × 50mm 2oz Cu), saturation performance, AEC-Q101 qualification, and complementary pairing with FZT593.

Technical Context

This NPN bipolar junction transistor operates in linear or saturated switching modes, supporting high-voltage DC loads up to 100V with low V_CE(sat) and robust ESD immunity (HBM = 4kV). Its f_T = 150MHz enables moderate-frequency switching in power control circuits.

The device features a thermally enhanced SOT223 package with exposed collector tab, enabling direct PCB copper pour attachment for improved heat dissipation. Thermal derating follows standard curves dependent on copper area and thickness, with R_θJL = 19.4°C/W confirming efficient junction-to-lead conduction.

Key Specifications

Pinout & Package

SOT223 package with molded green plastic case, UL 94V-0 rating, and exposed collector lead for thermal and electrical connection. Weight: 0.112 g. Moisture sensitivity level: J-STD-020 Level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN2012ZTA and MJD127G, the FZT493TC delivers superior thermal performance via its SOT223 exposed collector, tighter h_FE consistency for predictable base drive, and automotive-grade reliability - making it optimal for space-constrained, thermally demanding, and safety-critical 1A switching roles.

Availability

FZT493TC is available at Aetrix Electronics and suitable for automotive body control modules, industrial DC-DC converters, LED constant-current drivers, and smart home power relay interfaces requiring stable component supply across production lifecycles.

Supply support for FZT493TC 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 FZT493TC belongs to Diodes' high-reliability power transistor product line, engineered specifically for automotive and industrial applications demanding AEC-Q101 qualification, high-voltage tolerance, and thermally robust packaging.

FAQ

Is FZT493TC pin-compatible with FZT491 or FZT495?

No. FZT493TC uses SOT223 with Collector-Base-Emitter pinout (Tab = C, Pin 1 = E, Pin 2 = B, Pin 3 = C). FZT491 and FZT495 are in SOT-23 and SOT-89 packages respectively, with different pin assignments and thermal characteristics. Direct substitution is not possible without PCB redesign.

What is the maximum allowable PCB copper area for thermal optimization?

The datasheet specifies R_θJA = 41.7°C/W when mounted on 50mm × 50mm 2oz copper. Increasing copper area beyond this yields diminishing returns; minimum recommended layout (R_θJA = 104°C/W) uses only 12mm × 12mm pads. Use thermal vias under the collector tab to connect to internal ground planes for best results.

Does FZT493TC support pulsed operation above 1A?

Yes - it is rated for I_CM = 2A peak pulse current with ≤2% duty cycle and ≤300µs pulse width. This enables short-duration surge handling in motor startup or relay coil energization, provided average power remains within the 3.0W (or derated) limit based on ambient temperature and copper area.

Can FZT493TC replace a MOSFET in low-side switching applications?

It can function as a low-side switch, but differs fundamentally: as a bipolar transistor, it requires sustained base current (~100mA at 1A I_C) versus gate charge in MOSFETs. Use only where driver capability and thermal design accommodate BJT base drive losses; MOSFETs remain preferred for high-efficiency, high-frequency, or low-drive applications.