APW1172
Typical Operating Characteristics (Cont.)
Switching Frequency
258
Switching Frequenct (KHz)
256
254
252
250
248
246
244
-50
-25
0
25
50
75
100
125
Junction Temperature (
o
C)
Operating waveforms
1. Power ON (no SS) :
- V
IN
= 12V,V
OUT
= 3.3V
- C
IN
= 22µF, C
OUT
= 220µF, L = 15
µH
2. Power ON (external SS) :
- V
IN
= 12V,V
OUT
= 3.3V
- C
IN
= 22µF, C
OUT
= 220µF, L = 15
µH
I
L
I
L
V
OUT
V
IN
V
OUT
V
IN
COMP
Ch1 : V
OUT
,1V/div
Ch2 : COMP,2V/div
Ch3 : V
IN
,5V/div
Ch4 : I
L
,2A/div
Time : 400us/div
Ch1 : V
OUT
,1V/div
Ch2 : COMP,2V/div
Ch3 : V
IN
,5V/div
Ch4 : I
L
,2A/div
Time : 1ms/div
COMP
Copyright
©
ANPEC Electronics Corp.
Rev. A.4 - Aug., 2005
10
www.anpec.com.tw