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FMMT619 Transistor Data

Key transistor data for the FMMT619 transistor including key electrical parameters, pinout, package type and many other key transistor datasheet details.

The FMMT619 is a popular 50V NPN low saturation switching transistor in an SOT23 package. It has a higher operating voltage than the FMMT617 and FMMT618.

This electronic component combines a high voltage and power capability within the small surface mount SOT23 package making it particularly useful for many circuit design applications.

Key details and performance parameters for the FMMT619 transistor.

FMMT619 transistor datasheet parameters & data
Parameters	Details
Transistor type	NPN low saturation
Package type	SOT23
V_CBO max (V)	50V
V_CEO max (V)	50V
V_EBOmax (V)	7V
V_CEsat (V)	10mV typ, 20mV max @ I 0.1A & IB 10mA 125mV typ, 200mV max @ I 1 A & IB = 10mA 150mV typ, 220mV max @ I 2 A & IB = 50mA
I_C max (A)	2A
T_J Max °C	-55 - + 150°C
P_TOT W	625mW for given PCB heatsink area
f_T min (MHz)	100 min, 165 typ for IC = 50mA and VCE = 10V
C_OB	12pF typ, 20pF max
h_fe	200 min, 400 typ for IC = 10mA and VCE = 2V 300 min, 450 typ for IC = 200mA and VCE = 2V 200 min, 400 typ for IC = 1A and VCE = 2V 100 min, 225typ for IC = 2A and VCE = 2V
Similar / equivalents

Outline & pinout:

Explanation of transistor parameters

Parameter	Explanation
V_CBO Max	Maximum collector-base voltage with emitter open circuit .
V_CEO Max	Maximum collector-emitter voltage with base open circuit.
V_EBO Max	Maximum emitter-base voltage with collector open circuit.
V_CEsat (included where applicable)	The voltage drop across the collector-emitter when the transistor is fully saturated (acting as a closed switch).
I_C Max	Maximum collector current.

Parameter	Explanation
T_J	Maximum junction temperature.
P_TOT Max	Maximum device dissipation normally in free air at 25°C unless other conditions indicated.
f_T Min	Minimum cutoff frequency at which the current gain in a common emitter circuit falls to unity.
C_OB Max	Maximum collector capacitane, normally measured with emitter open circuit.
h_FE	DC current gain for H_FE at I_C. [Note hfe is the small signal gain and although this may be slightly different, the transistor current gain will vary considerably from ne transistor to the next of the same type.]
P_TOT Max	Maximum device dissipation normally in free air at 25°C unless other conditions indicated.

These are the main transistor parameters that have been included in our list. There are others, but these help quantify the main elements of the performance of the transistor.

Read more about . . . . Transistor Data-sheet Specifications & Parameters.

Please note, that the data given is the best estimate we can give within a tabulated summary of this nature. Parameters also vary between manufacturers. Electronics Notes cannot accept any responsibility for errors, inaccuracies, etc, although we do endevaour to ensure the data is as accurate as possible.

Notes and supplementary information

• Availability & sources

The FMMT619 is available from a number of stockists and electronic component distributors many of which are given in the table below.

FMMT619 Component Distributor, Stock and Pricing

• Notable features

The FMMT619 is a 50 V NPN silicon low saturation transistor in a compact SOT23 package, designed for efficient high-current switching and amplification in space-constrained applications.

Ultra-Low Saturation Voltage : VCE(sat) as low as 8 mV typical at 3 A, minimizing power losses in on-state operation.
High Continuous Collector Current : 3 A IC rating, with 12 A peak pulse capability for handling surges.
Excellent Current Gain : hFE maintained up to 100 at 12 A pulsed, enabling low base drive requirements.
High Power Dissipation : 625 mW in SOT23 package, with low thermal resistance for reliable performance.
Robust Voltage Rating : BVCEO > 50 V, suitable for medium-voltage switching circuits.
Wide Temperature Range : Operates from -55°C to 150°C, ideal for industrial and automotive use.
Fast Switching Characteristics : Optimized for rapid transitions in PWM and logic-level applications.
RoHS Compliant : Halogen- and antimony-free, with moisture sensitivity level 1 for easy assembly.

• Typical applications summary

Application Category	Typical Use Case	Device Feature Utilised
Switching Circuits	Relay and solenoid drivers in portable devices.	Low VCE(sat) (8 mV) and 3 A continuous current for efficient load control.
Power Management	DC-DC converters and battery protection switches.	12 A peak pulse and high hFE for transient handling and low drive power.
LED Drivers	High-brightness LED arrays in displays and lighting.	Ultra-low saturation voltage and 625 mW dissipation for minimal heat generation.
Audio Amplifiers	Output driver stages in small amplifiers.	Excellent hFE at high currents for distortion-free amplification.
Automotive Electronics	Sensor interfaces and control modules in vehicles.	Wide temperature range (-55°C to 150°C) and 50 V BVCEO for reliable operation.