IRF840 MOSFET

IRF840 MOSFET specification

• IRF840 is an N-channel POWER MOSFET device
• Drain to source voltage (V_DS) is 500V
• Gate to source voltage (V_GS) is +/- 20V
• Gate to the threshold voltage (V_{GS (th)}) is 2V to 4V
• Drain current (I_d) is 8A
• Pulsed drain current (I_DM) is 32A
• Power dissipation is (P_D) is 125W
• Total gate charge (Q_g) is 63nC
• Drain to source on-state resistance (R_{DS (ON)}) 85Ω
• Zero gate voltage drain current (I_DSS) is 25 to 250uA
• Rise time (tr) is 23ns
• Peak diode recovery dv/dt is 5V/ns
• Thermal resistance junction to ambient (R_th j-A) is 62℃/W
• Junction temperature (T_J) is between -55 to 150℃
• Body diode reverse recovery (trr) 460 to 970ns
• Input capacitance (C_iss) 1300pF
• Dynamic dv/dt rating
• Repetitive avalanche rated
• Fast switching
• Ease of paralleling
• Simple drive requirement
• Nanosecond switching speed
• Linear transfer characteristics
• High input impedance

IRF840 MOSFET Pinout

Pin Number	Pin Name	Description
1	GATE	In the source, terminal current flows out from the MOSFET
2	DRAIN	The gate terminal works as the trigger for the MOSFET
3	SOURCE	The drain is the input terminal of the MOSFET

 

IRF840 MOSFET package

The IRF840 MOSFET devices have the TO-220 package, it is packaging commonly comes in 3pin.

The TO-220 through-hole package is made as bulkier in size and lite weighted in mass, the epoxy/plastic material used to make this package for higher temperature resistance properties.

Another advantage of the TO-220 package is that it is a through-hole package, so we have the provision to attach a heat sink with the package.

We know IRF840 is a POWER MOSFET device, an exchange of higher power are been happen at the device, and so the TO-220AB package is a must thing for this MOSFET device.

IRF840 MOSFET electrical specification explanation 

In this section we try to explain the electrical specifications of IRF840 MOSFET, this spec explanation is really helpful for a better understanding of this device.

At the component selection process is much easier with this explanation and we try to add the application description of IRF840 MOSFET.

Voltage specs

The terminal voltage specification of IRF840 MOSFET is the drain to source voltage is 500V and gate to source voltage is +/-20V is the combined terminal voltage values

The gate to source threshold voltage value is 2 to 4V, it is the triggering voltage of the MOSFET.

The overall voltage specifications of IRF840 MOSFET show that it is a POWER device mainly used for the driver, switching, and converter applications.

Current specs

The drain current value of IRF840 MOSFET is 8A, it is the current value produced by this MOSFET device.

The pulsed drain current value is 32A, it is the current value produced in a specific condition.

The current value of the IRF840 MOSFET shows that they had an ability to withstand higher current at the load condition.

Zero gates voltage drain current

The value for zero gate voltage drain current is 25 to 250uA, it is a specific condition where the gate voltage is at zero and the current is a specific value with respect to voltage value.

Dissipation specs

The power dissipation value of IRF840 MOSFET is 125W, it is the power dissipation capacity of a MOSFET device in a thermal condition.

Drain to source on-state resistance

The drain to source on-state resistance is 0.85Ω, it is the overall resistance offered by the MOSFET.

Junction temperature

The junction temperature of the IRF840 MOSFET is –55 to +150℃.

Thermal resistance junction to ambient

The thermal resistance of IRF840 MOSFET is 62℃/W

Total gate charge

The total gate charge value of IRF840 is 63nC, it is the charge needed to trigger the MOSFET.

Rise time

The rise time value for IRF840 MOSFET is 23ns, it is the switching time offered by the MOSFET.

Peak diode recovery dv/dt

The peak diode recovery dv/dt value of IRF840 MOSFET is 3.5V/ns

Body diode reverse recovery time

The value is 460 to 970ns

IRFP460 MOSFET DATASHEET

If you need the datasheet in pdf please click this link

IRF840 MOSFET EQUIVALENT

The MOSFET devices such as IRF840A, IRF842, IRFS841, 2SK554, IRF744, 2SK2117, 2SK1805, and FTK480 are the equivalent MOSFET of IRF840 devices.

The electrical specifications of each of these equivalent MOSFETs are almost the same as IRF840, so we can easily replace them.

Before the replacement process, we need to check and verify the PINOUT details of the MOSFET device, this is because it is a high power device.

IRF840 vs IRF740 vs 2SK1805

In this table, we listed the electrical specifications of IRF840, IRF740, and 2SK1805 MOSFET devices, this is a much easier way to understand the MOSFET device.

Characteristics	IRF840	IRF740	2SK1805
Drain to source  voltage (VDS))	500V	400V	500V
Gate to source voltage (Vgs)	20V	20V	30V
Gate threshold voltage (Vg(th))	2 to 4V	2 to 4V	2 to 4V
Drain current (Id)	20A	6.3A	7A
Zero gate voltage drain current (I­DSS)	25 to 250uA	25 to 250uA	25 to 250uA
Total gate charge (Qg)	63nC	63nC	-
Power dissipation (PD)	125W	125W	45W
Junction temperature (TJ)	-55 to +150°C	-55 to +150°C	-55  to +150°C
Drain to source on-state resistance (RDS)	0.85Ω	0.55Ω	0.85Ω
Rise time (tr)	23ns	27ns	60ns
Reverse recovery time (trr)	460 to 970ns	370 to 790ns	-
Package	TO-220	TO-220AB	TO-220F

Characteristics curves of IRF840 MOSFET

The figure shows the output characteristics of IRF840 MOSFET, the graph is plotted with drain current vs drain to source voltage.

At the different gate to source voltage values, the drain current value will be increasing with respect to drain to source voltage.

The figure shows the on-state resistance of the IRF840 MOSFET device, the graph is plotted with on-state resistance vs temperature.

At the fixed drain current and gate to source voltage, the on-state resistance value increase from the lowest value to higher with respect to temperature.

The figure shows the maximum safe operating area of the IRF840 MOSFET device, the graph is plotted with drain current vs drain to source voltage.

Applications of IRF840 MOSFET

• Switching regulator
• Switching converter
• Motor drivers circuits
• Relay drivers
• DC-DC converter
• LED dimmer circuits
• Flasher circuits
• High power switching
• UPS
• DC motor driver system
• AC motor driver system
• Solar power applications
• Battery charger system