Diodes Incorporated FMMT734TA

Overview

FMMT734TA from Diodes Incorporated is a 100V PNP Darlington transistor in SOT23 package, delivering -800mA continuous collector current, >20,000 hFE at -100mA, and -100V VCEO rating. It serves as a high-gain switching or amplification element in low-power industrial control, relay drivers, and LED load interfaces where compact size and high DC gain are critical.

For engineers reviewing the FMMT734TA datasheet, FMMT734TA pinout, FMMT734TA application, or FMMT734TA equivalent, key selection criteria include its -100V breakdown voltage, Darlington gain retention up to -5A pulse, -0.72V VCE(sat) at -800mA/-5mA, thermal resistance of 155°C/W (pulsed), and AEC-Q101 qualification for automotive-adjacent reliability.

Technical Context

This PNP Darlington pair integrates two cascaded transistors to achieve ultra-high DC current gain while maintaining single-package simplicity. Its structure enables stable operation with base-emitter turn-on voltage of -1.3V and saturation voltage as low as -0.68V at modest drive currents.

The device supports high-voltage switching up to -100V with robust ESD protection (2kV HBM), operates across -55°C to +150°C, and features thermally optimized SOT23 packaging enabling 806mW pulsed power dissipation under defined PCB conditions.

Key Specifications

Pinout & Package

SOT23 surface-mount package with 3-terminal configuration: compact footprint (2.4 × 1.3 mm), 0.95 mm height, matte tin-plated leads, and UL 94V-0 flammability rating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP Darlington transistor applications.

Compared with ZTX951 and FMMT724, FMMT734TA uniquely combines SOT23 footprint, AEC-Q101 qualification, and >20k hFE-making it optimal for space-constrained, high-reliability high-side switching where gain and thermal performance are prioritized over raw power rating or polarity flexibility.

Availability

FMMT734TA is available at Aetrix Electronics and suitable for industrial relay drivers, automotive interior lighting control, low-power voltage regulator pass elements, and smoke detector audio alarm drivers requiring stable component supply and long-term manufacturability.

Supply support for FMMT734TA 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 industrial, automotive, and consumer markets.

FMMT734TA belongs to Diodes' FMMT series of high-voltage, high-gain SOT23 transistors designed specifically for compact, high-efficiency switching in space- and power-sensitive applications.

FAQ

What is the maximum safe operating voltage for FMMT734TA in continuous DC applications?

The absolute maximum collector-emitter voltage (VCEO) is -100V, verified per DS33121 Rev. 2-2. For reliable long-term operation, design should limit steady-state VCE to ≤ -80V to maintain margin against transients and temperature-induced derating, especially above +85°C ambient.

Does FMMT734TA include an integrated base resistor?

No, FMMT734TA is a bare Darlington transistor without internal base resistors. An external base current-limiting resistor must be used to ensure proper biasing-typical values range from 10kΩ (for logic-level drive) to 1kΩ (for fast switching), calculated based on required IB for target IC and VBE(on) ≈ -1.3V.

Can FMMT734TA be used in linear amplifier configurations?

Yes, but with caution: its high hFE and Darlington structure make it susceptible to thermal runaway in Class-A operation. Stable linear use requires strict thermal management, emitter degeneration resistors, and bias networks that compensate for hFE variation across temperature-verified designs typically limit PD to ≤300mW in analog mode.

How does the AEC-Q101 qualification impact FMMT734TA's suitability for non-automotive applications?

AEC-Q101 qualification confirms enhanced robustness-including extended temperature cycling (-55°C to +150°C), mechanical shock resistance, and accelerated lifetime testing-making FMMT734TA especially suitable for industrial equipment, medical peripherals, and outdoor electronics where reliability under thermal stress and vibration is critical, even outside automotive systems.