Data Sheet

© 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com
FAN8303 • Rev. 1.2 7
FAN8303 — 2 A 23 V Non-Synchronous Step-Down DC/DC Regulator
Typical Performance Characteristics (Continued)
V
IN
= 12 V, V
OUT
= 5 V, L1 = 15 μH, C
IN
= 10 μF, C
OUT
= 22 μF, T
A
= +25
o
C, unless otherwise noted.
Figure 10. Hard-Short at Output (OCP)
Figure 11. Overload at Output (OCP)
70
75
80
85
90
95
0 0.5 1 1.5 2
-1.5
-1
-0.5
0
0.5
1
-40 -15 10 35 60 85
Figure 12. Efficiency Curve
Figure 13. Normalized Output Voltage vs.
Temperature
320
330
340
350
360
370
380
-40 -15 10 35 60 85
2
2.5
3
3.5
4
0 20 40 60 80 100
Figure 14. Oscillator Frequency vs. Temperature
Figure 15. Current Limited Level vs. Duty Ratio
3.3Vo
2.5Vo
1.8Vo
CH1(VO) : 2V, 20µ/div.
CH2(VIN) : 4V, 20µs/div.
CH3(SW) : 6V, 20µs/div.
CH4(IL) : 2A, 20µs/div.
CH1(VO) : 2V, 20µ/div.
CH2(VIN) : 4V, 20µs/div.
CH3(SW) : 6V, 20µs/div.
CH4(IL) : 2A, 20µs/div.
CH1
CH2
C
H
3
CH4
CH4
C
H
3
CH1
CH2
△
f
=
4
5
k
H
z
Load Current [A]
Temperature [℃]
Temperature [℃]
Duty [%]
Efficiency [%]
Vout [%]
Load Current [A]
Frequency [kHz]
f=45kHz
5.0Vo