Welcome to the official website of Xi'an Semipower Electronic Technology Co., Ltd

A high-tech enterprise integrating R & D, production and sales

R&D New Products with Advanced Technology Leading-edge Technology

Semipower Electronic Technology Co.,Ltd

+86 29-88251977

Xi'an Semipower Electronic Technology Company-News Center-MOSFET Parameters Description
Semipower News centres

Semipower Science and technology

Wechat Public Number

MOSFET Parameters Description

Time:2019/5/20 10:57:36Number of visits:399


Absolute maximum ratings

Items

Parameter

Description 

VDSS

Drain to Source Voltage

Refer to BVDSS

ID

 Continuous Drain Current  (@TC=25oC)

The acceptable current value between drain and source. If the value is small, it will cause the risk of current breakdown in the system with insufficient derating design or in the test process of overload and current protection.

Continuous Drain Current (@TC=100oC)

IDM

Drain current pulsed

It reflects the single pulse current intensity that MOSFET drain source can bear. If the parameter is too small, when the power system is tested for overload and current protection, there is a risk of current breakdown.

VGS

Gate to Source Voltage

The maximum voltage range that the gate can bear. Under any condition, its connected voltage must be within the specification range. The gate of MOSFET is also the weakest part of MOSFET.

EAS

 Single pulsed Avalanche  Energy

The maximum single or multiple pulse energy that the MOSFET drain source can withstand. If the energy is too small, there is a risk of failure in surge, overload protection, withstand voltage and other test items.

EAR

 Repetitive Avalanche  Energy

dv/dt

Peak diode Recovery dv/dt

1dv / dt reflects the device's ability to withstand the rate of voltage change, the higher the better.

2For the system, high dv / dt will inevitably bring high voltage peak and poor EMI, but the rate of change can be corrected by the system circuit.

PD

Total power dissipation  (@TC=25oC)

The value is the higher , the better. Because the test of the value is to simulate the ideal environment, the test value is very different from the actual application, and the reference significance is relatively limited.

Derating Factor above 25oC

TSTG,  TJ

Operating Junction  Temperature & Storage Temperature

This parameter shows that the temperature tolerance of MOSFET is better. The higher, the better.

TL

Maximum Lead Temperature  for soldering

This parameter is for plug-in products. The higher the value is, the better the temperature tolerance during welding.

purpose, 1/8 from Case for 5 seconds.


Thermal characteristics

Item

Parameters

Description

Rthjc

Thermal resistance, Junction to case

The parameters show that the heat dissipation ability of the device  under the same heating condition, and the smaller the thermal resistance is, the better the heat dissipation ability is.

Rthcs

Thermal resistance, Case to Sink

Rthja

Thermal resistance, Junction to ambient

Item

Parameters

Description

IS

Continuous source current

The maximum continuous current that can be borne between drain and source. If the value is small, it will cause the risk of current breakdown in the process of overload and current protection test for the system with insufficient derating.

ISM

Pulsed source current

It reflects the single pulse current intensity that MOSFET drain source can bear. If the parameter is too small, when the power system is tested for overload and current protection, there is a risk of current breakdown.

VSD

Diode forward voltage drop.

If the parameter is too high, the system loss and temperature rise will be too high in the bridge or LLC system.

Trr

Reverse recovery time 

If the parameter is too high, the system loss and temperature rise will be too high in the bridge or LLC system. At the same time, it also increases the risk of circuit through.

Qrr

Reverse recovery Charge

This parameter is directly proportional to the charging time, generally the smaller the better.



Electrical characteristic

( TC = 25oC unless otherwise specified )

Item

Parameters

Description

 Off characteristics

BVDSS

Drain to source breakdown voltage

The maximum withstand voltage of drain to source. It is positive temperature coefficient. If BVDSSis too small, it will cause MOSFET overvoltage failure when applied to the system board with insufficient margin.

ΔBVDSS/ ΔTJ

Breakdown voltage temperature   coefficient

The positive temperature coefficient reflects the temperature stability of BVDSS. The smaller the value is, the better the stability is.

IDSS

Drain to source leakage current

The Higher the positive temperature coefficient and IDSS, the higher the static loss of MOSFET when it is turned off, which will lead to the deterioration of temperature rise.

IGSS

Gate to source leakage current, forward

Gate leakage current, the smaller the better, which has a small impact on system efficiency.

Gate to source leakage current, reverse

 On characteristics

VGS(TH)

Gate  threshold voltage

(1) Under the same ID and transconductance conditions, the higher the VGS (th), the higher the MOSFET Miller platform.

(2) It directly reflects the threshold voltage of MOSFET. The gate driving voltage must be higher than the platform voltage when MOSFET works. If the gate driving voltage works near the platform for a long time, the device will not be fully opened, and the internal resistance will rise sharply, resulting in the corresponding thermal failure of the device.

RDS(ON)

Drain  to source on state resistance

The smaller the MOSFET RDS(ON)  with  the same specification, the better. It directly determines the conduction loss of MOSFET. The higher the RDS(ON), the greater the loss, and the higher temperature rise of MOSFET. For large power supply, RDS(ON) loss accounts for a large proportion of MOSFET loss.

The change of RDS(ON) will cause the change of the overcurrent protection point of the customer system board.

Gfs

Forward Transconductance

It reflects the gate voltage's ability to control the drain to source current. Too small Gfs will reduce the MOSFET's turn off speed, reduce the turn off ability, and too high Gfs will lead to too fast turn off and poor EMI characteristics. At the same time, when the drain source is turned off, it will produce higher turn off voltage spike.

Dynamic characteristics

Ciss

Input capacitance

This parameter affects the switching time of MOSFET. The higher the Ciss is, the slower the opening and closing time and the greater the switching loss will be under the same driving capacity. This is also the reason why the acceleration circuit should be added in the power circuit. But the slower switch speed will bring better EMI characteristics.

Coss

Output capacitance

These two parameters have an impact on the switching time of MOSFET, among which Cgd will affect the magnitude of voltage energy transmitted to the gate of MOSFET when the drain to source voltage is abnormal, which will have a certain impact on the surge test items.

Crss

Reverse  transfer capacitance

td(on)

Turn on delay time

These parameters are time related parameters. The faster the switching speed, the less the switch loss, the higher the efficiency and the lower the temperature rise. The corresponding disadvantages are the poor EMI characteristics and the high MOSFET off peak.

tr

Rising time

td(off)

Turn off delay time

tf

Fall time

Qg

Total gate charge

Qgs

Gate-source charge

Qgd

Gate-drain charge