SC4605IMSTR View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'SC4605IMSTR' PDF : 19 Pages View PDF
SC4605
POWER MANAGEMENT
Applications Information (Cont.)
Over current protection characteristic of SC4605 for 3.3V to 1.5V @12A application
The over current protection curve below is obtained by applying a gradually increased load while the load current
and the output voltage are monitored and measured. When the load current is increased from 0 to 16.2A (over
current trigger point), the output voltage is 1.5V, corresponding from Point A to Point B. As the load current in-
creases further from 16.2A to 16.3A, the output voltage drops significantly from 1.5V (Point B) to 0.88V (Point C).
Because an over current and a lower output voltage (0.88V<68.75%*1.5V=1.03V) are present at Point C, the
SC4605 enters its HICCUP mode. Then the locus of the output current and the output voltage follows Line CD as
shown in the curve. Due to the over current applied, the HICCUP protection will go back and forth on Line CD. This
prevents excess power dissipation in the TOP MOSFET during a short output condition.
3
2.5
2
1.5
1
0.5
0
0
Over current protection
A
B
D
5
10
15
Io (A)
C
20
2004 Semtech Corp.
17
www.semtech.com
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