SC4602A Datasheet, PDF (17/18 Pages) Semtech Corporation – High Efficiency Synchronous, Step Down Controller

SC4602A/B
POWER MANAGEMENT
Typical Characteristic
Over current protection characteristic of SC4602B for 3.3V to1.5V @6A 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 9A (over current
trigger point), the output voltage is 1.5V, corresponding from Point A to Point B. As the load current increases
further from 9A to 9.6A, the output voltage drops significantly from 1.5V (Point B) to 0.54V (Point C). Because an
over current and a lower output voltage (0.54V<68.75%*1.5V=1.03V) are present at Point C, the SC4602B 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 P-MOSFET during a short output conditio
Overcurrent protection
3
2.5
A
B
2
1.5
1
D
C
0.5
0
0
3
6
9
12
15
18
Output Current (A)
 2006 Semtech Corp.
17
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