Diodes Incorporated FMMT617TC

Overview

FMMT617TC from Diodes Incorporated is a 15V NPN low-saturation transistor in SOT23 package, rated for 3A continuous collector current, 12A peak pulse current, and 50mΩ R_CE(sat). It delivers high-current gain (h_FE = 320 at I_C = 3A) and operates across –55°C to +150°C, serving as a power switch in DC-DC modules and LED drivers.

For engineers reviewing the FMMT617TC datasheet, FMMT617TC pinout, FMMT617TC application, or FMMT617TC equivalent, key selection criteria include V_CEO = 15V, I_C = 3A, R_CE(sat) ≤ 150mV at 3A/50mA drive, thermal resistance R_θJA = 155°C/W (t ≤ 5s), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This NPN bipolar junction transistor is optimized for high-efficiency switching in compact power stages. Its low V_CE(sat) (≤150mV at 3A) and high h_FE (≥320 @ 3A) reduce conduction loss and base drive burden, while its 12A I_CM rating supports short-duration surge handling in regulator and inverter circuits.

The device uses a thermally enhanced SOT23 package with matte tin-plated leads and meets J-STD-020 Level 1 moisture sensitivity. Its 80–120MHz f_T, 30–40pF C_obo, and sub-300ns total switching time (t_on + t_off) support medium-frequency switching up to several hundred kHz.

Key Specifications

Pinout & Package

SOT23 plastic surface-mount package with 3-pin configuration: emitter (E), base (B), collector (C); dimensions per AP02002 (L × W × H ≈ 2.9 × 1.35 × 1.0 mm); weight ≈ 0.008 g; UL 94V-0 flammability rating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN low-saturation transistor applications.

Compared with ZXTN2012ZTA and FMMT614TC, FMMT617TC uniquely balances 15V rating, 3A continuous current, and 150mV saturation at full load-making it optimal for cost-sensitive 12V automotive and industrial switching where thermal margin and drive simplicity are prioritized.

Availability

FMMT617TC is available at Aetrix Electronics and suitable for DC-DC converters, LED drivers, and CCFL backlighting inverters requiring stable component supply and AEC-Q101-compliant performance.

Supply support for FMMT617TC 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 power management, signal integrity, and protection solutions.

The FMMT617TC belongs to Diodes' FMMT series of low-saturation bipolar transistors, engineered for high-current switching in space-constrained automotive and industrial power stages.

FAQ

What is the maximum continuous collector current for FMMT617TC at 70°C ambient?

At T_A = 70°C, the maximum continuous collector current is derated to approximately 2.1A based on the 155°C/W R_θJA (t ≤ 5s) and 150°C maximum junction temperature. This follows the linear derating curve shown in Figure 2 of DS36156 Rev. 4-2, where power dissipation drops from 806mW at 25°C to ~450mW at 70°C.

Is FMMT617TC pin-compatible with FMMT614TC or FMMT618TC?

Yes - all three share identical SOT23 pinout (E-B-C) and mechanical footprint. However, FMMT614TC has 25V V_CEO/2A I_C, while FMMT618TC offers 20V V_CEO/2.5A I_C; neither matches FMMT617TC's 15V/3A combination, so electrical substitution requires circuit validation.

Does FMMT617TC require a base resistor in typical switching applications?

Yes - a base current of 50mA is required to saturate the device at 3A collector current. With typical V_BE(sat) ≈ 0.9V and driver voltage of 3.3V or 5V, a 47Ω–100Ω series resistor ensures proper base drive while limiting driver loading and preventing thermal runaway.

Can FMMT617TC be used in linear regulator configurations?

Yes - its 15V V_CEO, 3A I_C, and stable h_FE make it suitable as a series pass transistor in adjustable linear regulators. Designers must ensure junction temperature remains below 150°C using appropriate heatsinking or current limiting, especially at high V_IN–V_OUT differentials.