STD90NH02L ST Microelectronics, Inc., STD90NH02L Datasheet - Page 10

• Manufacturer Part Number: STD90NH02L
• Description: N-channel 24V - 0.0052 Ohm - 60A Dpak/ipak StripFET Iii Power MOSFET
• Manufacturer: ST Microelectronics, Inc.

STD90NH02L
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The power losses associated with the FETs in a Synchronous Buck converter can be
estimated using the equations shown in the table below. The formulas give a good
approximation, for the sake of performan ce comparison, of how different pairs of devices
affect the converter efficiency. However a very important parameter, the working
temperature, is not considered. The real device behavior is really dependent on how the
heat generated inside the devices is r e moved to allow for a safer working junction
temperature.
The low side (
The high side (
Very low R
Small Q
Small C
Small Q
The C
voltage to avoid the cross conduction phenomenon;
Small R
feedback on the gate
Small Q
Low R
Buck Converter: Power Losses Estimation
gd
SW2
DS(on)
SW1)
oss
rr
gls
/C
g
g
to have a faster commutation and to reduce gate charge losses
to reduce losses on SW
gs
to reduce the gate charge losses
to reduce losses due to output capacitance
and L
) device requires:
DS(on)
to reduce the conduction losses.
device requires:
ratio lower than V
to reduce conduction losses
s
to allow higher gate current peak an d to limit the voltage
SW1
APPENDIX A
SW2
th
1
/V
during its turn-on
gg
ratio especially with low drain to source