MB3782PF FUJITSU [Fujitsu Component Limited.], MB3782PF Datasheet - Page 23

• Manufacturer Part Number: MB3782PF
• Description: ASSP Power Supplies BIPOLAR Switching Regulator Controller
• Manufacturer: FUJITSU [Fujitsu Component Limited.]

Graph 2
Graph 3
• Reference data
Changing the smoothing capacitor from an aluminum electrolytic capacitor (RC
conductor electrolytic capacitor (OS capacitor: RC
– 20
– 40
– 20
– 40
60
40
20
60
40
20
0
0
10
10
DC/DC converter + 5 V output frequency vs.gain and phase
DC/DC converter + 5 V output frequency vs.gain and phase
Figure 8 Measurement of DC/DC Capacitor AV and Phase ( ) Characteristics
FB
100
100
Av
Av
Error amp
C
Frequency f (Hz)
NF
Frequency f (Hz)
–
+
1 k
1 k
V
REF
– IN
+ IN
/2
V out
62°
R
1
10 k
10 k
R
Vcc = 10 v
R
Cp = 0.1 F
2
Vcc = 10 v
R
Cp = 0.1 F
27°
L
L
0.2 ) decreases the phase margin (see Graphs 2, 3).
= 25
= 25
V
IN
100 k
100 k
180
90
0
– 90
– 180
180
90
0
– 90
– 180
A
measured between these points
V
V
0 +
and phase characteristics
1.0 ) to a lower-ESR semi-
+
–
+
–
OS capacitor
22 F (16 V)
R
Aluminum electrolytic
capacitor
220 F (16 V)
R
fosc = 1 kHz
C
fosc = 1 kHz
MB3782
C
0.2
1.0
V
0 +
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