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MB3778 Datasheet, PDF (24/29 Pages) Fujitsu Component Limited. – Switching Regulator Controller | |||
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MB3778
Reference data
If an aluminum electrolytic smoothing capacitor (RC â
1.0 â¦) is replaced with a low ESR electrolytic capacitor(OS
CONTM : RC â
0.2 â¦), the phase margin is reduced by half(see Fig. 37 and 38).
DC/DC Converter AV vs. Ï characteristic Test Circuit
VOUT
VO+
CNF
AV vs. Ï characteristic
Between these points
âIN
FB
VIN
+IN
R2
R1
VREF/2
Error Amp.
60
40
20
0
â20
â40
10
60
40
20
0
â20
â40
10
24
DC/DC Converter +5 V output Gain vs. Phase
AV
100
VCC = 10 V
RL = 25 â¦
CP = 0.1 µF
180
Ï
90
62 °
0
â90
â180
1k
10 k
100 k
VO+
AI Capacitor
+
220 µF (16 V)
â RC â
1.0 ⦠: fOSC = 1 kHz
GND
Figure 38 DC/DC Converter +5 V output Gain vs. Phase
VCC = 10 V
AV
RL = 25 â¦
CP = 0.1 µF
180
90
Ï
27 °
0
â90
100
1k
10 k
Frequency f (Hz)
â180
100 k
VO+
OS CONTM
+
22 µF (16 V)
â RC â
0.2 ⦠: fOSC = 1 kHz
GND
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