ST1S14 STMicroelectronics, ST1S14 Datasheet - Page 30

• Manufacturer Part Number: ST1S14
• Description: Up to 3 A step down switching regulator
• Manufacturer: STMicroelectronics

Application information
30/42
The content given in
Equation 40
The
(1.45A) given in
Equation 40
voltage divider over the entire input voltage range (see
In most of the application conditions the pulse by pulse current limitation with frequency
foldback is effective to limit the inductor current in short circuit condition. The current
foldback helps to decrease the power component stress in persistent short circuit condition.
The hiccup protection offers an additional protection against heavy short circuit condition at
very high input voltage even considering the spread of the minimum conduction time of the
power element. In case the hiccup current level (6.2A typical) is triggered the switching
activity is prevented for 15ms and then a new soft start phase takes place.
Figure 19. Minimum V
Figure 20
current to the peak current of 1.45A typical during a short circuit event.
Figure 19
shows the effectiveness of the constant current protection limiting the inductor
expresses the worst case scenario as it considers the minimum K gain of the
plots the
Table 6: Electrical characteristics on page
Chapter 7.4.1
V
FB
Equation 40
(
FB
V
IN
for effective pulse by pulse protection over VIN
)
Doc ID 17977 Rev 1
=
1.22
---------- -
5
is valid and the equivalent expression of
considering the foldback current limitation threshold
–
⎛
⎝
-----------------------------------
V
1.22 T
IN
⋅
T
⋅
ON_MIN
SW
⋅
(
V
Figure
D
+
6.
(
I
L
⋅
14).
DCR
)
)
⎞
⎠
Equation 37
ST1S14
is: