Diodes Incorporated FMMT624TC

Overview

FMMT624TC from Diodes Incorporated is a 125V NPN low-saturation transistor in SOT23 package, designed for high-voltage switching with 1A continuous collector current, 160mΩ R_CE(sat), and AEC-Q101 qualification. It serves as a robust switch in DC-DC modules, LED drivers, and CCFL backlight inverters where high breakdown voltage and low conduction loss are critical.

For engineers reviewing the FMMT624TC datasheet, FMMT624TC pinout, FMMT624TC application, or FMMT624TC equivalent, key selection criteria include V_CEO = 125V, I_C = 1A, R_CE(sat) ≤ 160mΩ at I_C = 1A/I_B = 50mA, h_FE ≥ 140 at 1A, and SOT23 thermal performance under pulsed and DC conditions.

Technical Context

This NPN bipolar junction transistor operates with a minimum BV_CEO of 125V and supports up to 3A peak pulse current, enabling reliable high-voltage switching in compact power stages. Its low 160mΩ saturation resistance and specified h_FE up to 3A ensure stable gain retention under high-current load conditions.

The device features a thermally optimized SOT23 package with R_θJA = 200°C/W (steady-state) and R_θJL = 194°C/W, supporting operation from –55°C to +150°C. ESD ratings meet 4kV HBM and ≥400V MM per JEDEC standards.

Key Specifications

Pinout & Package

SOT23 plastic surface-mount package 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 high-voltage switching transistor applications.

Compared with ZXTN2010Z and MMBT6427, the FMMT624TC delivers superior voltage margin (125V), lowest R_CE(sat), and highest h_FE at 1A-making it optimal for 100V+ industrial and automotive switching where reliability and conduction loss are critical.

Availability

FMMT624TC is available at Aetrix Electronics and suitable for DC-DC converters, LED drivers, and CCFL backlight inverters requiring stable component supply, AEC-Q101 compliance, and consistent SOT23 packaging across production lots.

Supply support for FMMT624TC 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 FMMT624TC belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for compact, high-efficiency switching in power conversion and lighting control applications demanding AEC-Q101 qualification and low R_CE(sat).

FAQ

What is the maximum continuous collector current for FMMT624TC at 70°C ambient?

At T_A = 70°C, the maximum continuous collector current is derated to approximately 0.75A based on the 625mW power dissipation limit and R_θJA = 200°C/W. This assumes mounting on a 25mm × 25mm FR4 board with 1oz copper and still-air conditions.

Is FMMT624TC suitable for linear regulator applications?

Yes - its 125V V_CEO, 625mW P_D, and stable h_FE support use as a pass transistor in medium-current linear regulators. However, thermal design must account for R_θJA = 200°C/W; for >100mA loads at high input-output differentials, heatsinking or forced airflow is recommended.

Does FMMT624TC have a documented safe operating area (SOA) curve?

Yes - the official DS33110 datasheet includes a SOA graph (page 3) showing DC and pulsed limits up to 100ms. The curve confirms safe operation at 125V/1A DC and extends to 3A/100V for 10ms pulses, validating use in transient-heavy applications like CCFL ignition.

What is the base-emitter saturation voltage at rated 1A collector current?

V_BE(sat) is 0.85V typical and 1.0V maximum at I_C = 1A and I_B = 50mA (per datasheet page 4). This ensures predictable base drive power (~50mW) and simplifies gate-driver or microcontroller GPIO interface design.