AN-4163 Datasheet, PDF (1/10 Pages) Fairchild Semiconductor – Shielded Gate PowerTrench MOSFET Datasheet Explanation

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AN-4163 — Shielded Gate PowerTrench®
MOSFET Datasheet Explanation
Introduction
A MOSFET datasheet contains important technical
information for power system designers to choose proper
MOSFETs for specific applications. This application note
explains the electrical parameters and graphs specified in
datasheets PowerTrench® MOSFETs. The shielded gate
PowerTrench is Fairchild’s advanced trench MOSFET
design technology that supports MOSFETs rated up to
300 V. In this application note, the 100 V N-channel
FDMS86101A datasheet is used for explanation.
1. Drain-to-Source Breakdown
Voltage, BV_DSS
The breakdown voltage between the drain and the source
terminal, BV_DSS, is measured at 250 µA drain current, I_D,
with the gate shorted to the source, which turns off the
MOSFET, as shown in Figure 1. Table 1 provides the
minimum value of BV_DSS at 25°C junction temperature, T_J.
The level of the BV_DSS is proportional to the increase of T_J
positively. For example, the breakdown voltage temperature
coefficient of FDMS86101A, ^BVDSS is 71 mV/°C
T_J
typically. If T_J of FDMS86101A reaches 100°C, the BV_DSS
increases by 5.325 V (75°C x 71 mV/°C). For more reliable
operation, special caution should be taken to not exceed the
BV_DSS; especially at an inductive load condition.
Drain
Gate
DUT
I_D
Source
Figure 1. Drain-to-Source Breakdown Voltage Test Circuit
Table 1. Drain-to-Source Breakdown Voltage
Parameters
Symbol Parameter Conditions Min. Typ. Unit
Drain-to-
BVDSS
Source
Breakdown
ID = 250 µA,
VGS = 0 V
100
V
Voltage
BV_DSS
T_J
Breakdown _{ID = 250 µA,}
Voltage
Referenced to
Temperature
Coefficient
25°C
71
mV/°
C
2. Gate-to-Source Voltage, V_GS
The sustainable voltage between the gate and the source
terminal is limited to the maximum voltage, V_GS. It has the
positive and negative 20 V, shown in Table 2, and any gate
drive voltage must be less than the maximum V_GS.
Designers should check the datasheet value for reliable
operation since the V_GS varies by MOSFET technology.
Table 2. Gate to Source Voltage Parameters
Symbol
Parameter
Ratings Unit
VGS
Gate to Source Voltage
±20
V
3. Gate-to-Source Threshold
Voltage, V_GS(th)
The gate-to-source threshold voltage, V_GS(th), is defined
as a minimum gate electrode bias to conduct the 250 µA
drain current, I_D. It has the negative temperature
V_{GS(th )}
coefficient, ^TJ so it is decreased as the junction
temperature, T_J rises. For example, when T_J of
FDMS86101A becomes 100°C, V_GS(th) is reduced by
0.675 V (75°C x -9 mV/°C). Minimum, typical, and
maximum values are specified in Table 3.
© 2013 Fairchild Semiconductor Corporation
Rev. 1.0.1 • 10/23/14
www.fairchildsemi.com