a5975d STMicroelectronics, a5975d Datasheet - Page 28

• Manufacturer Part Number: a5975d
• Description: Up To 3 A Step-down Switching Regulator For Automotive Applications
• Manufacturer: STMicroelectronics

Application information
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●
Equation 24
where T
switching losses when driving an inductive load (see
switching time.
Figure 14. Switching losses
●
Equation 25
where I
Example:
R
150 °C. We can consider a value of 0.4 Ω.
T
I
Q
SW
DS(on)
has a typical value of 5 mA @ V
Switching losses due to turning on and off. These are derived using the following
equation:
Quiescent current losses.
–
–
–
is approximately 70 ns.
Q
has a typical value of 0.25 @ 25 °C and increases up to a maximum value of 0.5. @
RISE
is the quiescent current.
V
V
I
OUT
OUT
IN
and T
= 12 V
= 3 A
P
= 3.3 V
SW
FALL
=
V
represent the switching times of the power element that cause the
IN
⋅
I
OUT
Doc ID 018760 Rev 1
⋅
(
----------------------------------- - F
T
IN
ON
= 12 V.
P
+
2
Q
T
OFF
=
V
)
IN
⋅
⋅
SW
I
Q
=
Figure
V
IN
⋅
I
OUT
14). T
⋅
T
SW
SW
⋅
F
is the equivalent
SW
A5975D