Buck convert
STD70N02L - STD70N02L-1
Table 8.
Power losses
High side switch (SW1)
Pconduction
RDS(on) • IL2 • δ
Low side switch (SW2)
RDS(on) • IL2 • (1 – δ)
Pswitching
Vin
•
(Qgsth(SW1)
+
Qgd(SW1))
•
f
•
I--L-
Ig
Pdiode
recovery
conduction
Not applicable
Not applicable
Pgate(Qg)
Qg(SW1) • Vgg • f
Zero voltage switching
1Vin • Qrr(SW2) • f
Vf(SW2) • IL • tdeadtime • f
Qgls(SW2) • Vgg • f
PQoss
V-----i-n----•-----Q-----o---s---s--(--S----W----1---)---•-----f
2
-V----i-n----•-----Q-----o---s---s--(--S----W----2---)---•-----f
2
Table 9. Power losses parameters
Paramter
Meaning
d
Duty-cycle
Qgsth
Qgls
Pconduction
Post threshold gate charge
Third quadrant gate charge
On state losses
Pswitching
On-off transition losses
Pdiode
Conduction and reverse recovery diode losses
Pgate
Gate driver losses
PQoss
Output capacitance losses
10/17