Datasheet

Application information A5972D
22/37 Doc ID 13956 Rev 5
compensate for the losses in the overall application. For this reason, the switching losses
related to the R
DSON
increases compared to an ideal case.
● Switching losses due to turning ON and OFF. These are derived using the following
equation:
Equation 23
Where T
RISE
and T
FALL
represent the switching times of the power element that cause the
switching losses when driving an inductive load (see Figure 12). T
SW
is the equivalent
switching time.
Figure 12. Switching losses
● Quiescent current losses.
Equation 24
Where I
Q
is the quiescent current.
Example:
–V
IN
= 12 V
–V
OUT
= 3.3 V
–I
OUT
= 1.5 A
P
SW
V
IN
I
OUT
T
ON
T
OFF
+()
2
------------------------------------
•• F
SW
V
IN
=• I
OUT
T
SW
• F
SW
••=
P
Q
V
IN
I
Q
•=