Diodes Incorporated FMMT493TA

Overview

FMMT493TA from Diodes Incorporated is a 100V NPN medium-power transistor in SOT23 package, rated for 1A continuous collector current and 500mW power dissipation, with guaranteed hFE ≥100 at IC = 1mA and VCE = 10V. It serves as a high-voltage switching or linear amplification device in industrial power supplies, LED drivers, and automotive load control circuits.

For engineers reviewing the FMMT493TA datasheet, FMMT493TA pinout, FMMT493TA application, or FMMT493TA equivalent, key selection criteria include BVCEO ≥100V, ICM = 2A peak pulse capability, VCE(sat) ≤600mV at IC = 1A/IB = 100mA, thermal resistance RθJA = 250°C/W on 15mm × 15mm FR4, and AEC-Q101 qualification status for automotive-grade reliability.

Technical Context

This NPN bipolar junction transistor operates with a minimum BVCEO of 100V and supports DC switching up to 1A, with pulsed operation extending to 2A (ICM). Its fT = 150MHz enables use in medium-frequency amplification and fast-switching applications.

The device features low VBE(sat) = 1.15V at IC = 1A/IB = 100mA and exhibits tight hFE characterization across 1mA–1A, supporting stable gain in both linear and saturated switching modes. ESD robustness includes HBM rating of 4kV and MM ≥400V.

Key Specifications

Pinout & Package

Package: SOT23 (Type DN), surface-mount plastic case with matte tin-plated leads, moisture sensitivity level 1 per J-STD-020, weight ≈0.008g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN2012ZTA and MMBT4401, FMMT493TA uniquely balances 100V blocking, 1A continuous current, and AEC-Q101 readiness-making it optimal for 24–48V industrial and automotive load switching where reliability and voltage margin are jointly critical.

Availability

FMMT493TA is available at Aetrix Electronics and suitable for industrial power supplies, automotive LED drivers, and programmable logic outputs requiring stable component supply and traceable sourcing.

Supply support for FMMT493TA 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 FMMT493TA belongs to Diodes' high-reliability discrete transistor product line, engineered for robust switching and amplification in harsh environments including automotive under-hood and industrial control systems.

FAQ

What is the maximum safe operating voltage for FMMT493TA in DC switching applications?

The absolute maximum collector-emitter voltage (VCEO) is 100V under DC conditions at TA = +25°C. Derating is required above 25°C ambient: VCEO decreases linearly to 0V at +150°C junction temperature. For reliable long-term operation, design with ≤80V VCE in continuous use at 70°C ambient to maintain safety margin against transients and temperature drift.

Does FMMT493TA require a heatsink in standard SOT23 mounting?

No external heatsink is required for FMMT493TA when dissipating ≤500mW on a 15mm × 15mm 1oz copper FR4 PCB in still air. Its RθJA = 250°C/W yields a junction-to-ambient rise of 125°C at full rated power. For sustained 1A switching at elevated ambient temperatures (>50°C), increase copper area or add thermal vias-but no clip-on heatsink is compatible with SOT23 geometry.

Is FMMT493TA pin-compatible with FMMT593?

No-FMMT493TA (NPN) and FMMT593 (PNP) share the same SOT23 package and pinout order (E-B-C), but their complementary polarity means direct substitution would invert logic states and cause circuit failure. They are electrically complementary-not mechanically interchangeable-requiring redesign of biasing and signal paths when swapping.

Can FMMT493TA be used in Class D amplifier output stages?

FMMT493TA is not recommended for Class D amplifier output stages due to its relatively slow turn-off time (not specified in datasheet) and lack of optimized SOA for repetitive high-frequency switching. While fT = 150MHz suggests theoretical RF capability, its safe operating area curve shows significant derating above 100kHz pulse widths, making it better suited for <50kHz switching or linear amplification rather than audio-band PWM output.