ACT4088
Rev0, 13-May-08
Figure 3:
ACT4088 Optimized for Minimal External Components
The ACT4088 with provides excellent AC and DC results across a wide range of external component combinations. The circuit of
Figure 3 can be used to generate a 5V output from a 12V input utilizing a smaller (i.e. lower-cost) output capacitor while maintaining
good performance.
6
2
3
BST
VIN
IN
C3
22nF
C1
10µF
L1
4.7µH
1
VOUT
5V
ACT4088 SW
D1
B240A
C2
4.7µF
ON
EN
RFB1
OFF
4
FB
150k?ꢀ
G
28.7k?ꢀ
1%
RFB2
1%
5
Figure 5:
Figure 4:
Circuit of Figure 3 (ILOAD = 1A)
Circuit of Figure 3 (ILOAD = 150mA to 850mA)
Circuit of Figure 3
Circuit of Figure 3
ILOAD = 1A
I
LOAD = 150mA to 850mA
CH1
CH2
CH1
CH2
CH1: ILOAD, 500mA/div
CH1: VSW, 10V/div
CH2: VOUT, 100mV/div (AC Coupled)
TIME: 200µs/div
CH2: VOUT, 20mV/div (AC Coupled)
TIME: 400ns/div
Innovative PowerTM
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