FAN5353 Datasheet, PDF (6/13 Pages) Fairchild Semiconductor – 3MHz, 3A Synchronous Buck Regulator

Typical Characteristics
Unless otherwise specified, VIN = 5V, VOUT = 1.2V, circuit of Figure 1, and components per Table 1.
VOUT
IL
Iload
Figure 9. Load Transient Response: 100mA to 1.5A to
100mA, tr=tf=100ns, Horizontal Scale = 5µs/div.
Figure 10. Load Transient Response: 500mA to 3A to
500mA, tr=tf=100ns, Horizontal Scale = 5µs/div.
20
18
5VIN,1.2VOUT
16
3.3VIN,1.2VOUT
14
5VIN, 3.3VOUT
12
10
8
6
4
2
0
0.1
1
10
100
1000
10000
Load Current (mA)
3.5
3.0
2.5
2.0
1.5
VIN = 4.1V
VIN = 4.0V
1.0
VIN = 3.9V
VIN = 3.8V
0.5
-
0
0.5
1
1.5
2
2.5
3
Load Current (A)
Figure 11. Output Voltage Ripple vs. Load Current
Figure 12. Effect of tOFF Minimum on Reducing the
Switching Frequency at Large Duty Cycles, VOUT = 3.3V
90
80
70
60
50
1.2VOUT,1.5A load
40
1.2VOUT, 3A load
30
3.3VOUT,1.5A load
20
0.01
0.1
1
10
100
Frequency (KHz)
Figure 13. Power Supply Rejection Ratio
V IN
VOUT
Figure 14. Line Transient Response with 1A load, 10µs/div.
© 2009 Fairchild Semiconductor Corporation
FAN5353 • Rev. 1.0.2
6
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