AN8018 Panasonic Semiconductor, AN8018 Datasheet - Page 20

• Manufacturer Part Number: AN8018
• Description: 1.8-volt 2-channel step-up/ step-down/ or inverting DC-DC converter control IC
• Manufacturer: Panasonic Semiconductor

AN8018SA
20
[9] About sequential operation (continued)
[10] Error amplifier phase-compensation setting method
required to have a gain on the high frequency side or desired to lead a phase.
Application Notes (continued)
Figure 11. Error amplifier equivalent circuit
The equivalent circuit of error amplifier is as shown in figure 11.
The transfer function is:
H
The cut-off frequency is variable by changing the externally attached phase compensation capacitor C
Adjust by inserting a resistor R
The transfer function is:
H
IN 1
V
V
DT1
Out1
DT2
Out2
1
2
R
SC
E1
1 / {S (C
O1
SC
(R
1 / {S (C
O1
1.19 V
O1
57dB
· R
E1
O1
R
E1
E1
1 M
C
)
5 pF
R
1
C
O1
E1
E1
C
)}
1 (from C
O1
)}
To PWM
Operation when each channel single on/off
O1
C
between the FB1 terminal and C
SC
O1
E1
O1
· R
1
C
E1
O1
Out1 operation
Out2 operation
)
1
Figure 12. Error amplifier equivalent circuit (R
(from C
IN 1
E1
C
O1
O1
in series as shown in figure 12 when it is
1.19 V
)
57dB
1 M
5 pF
R
C
E1
E1
Voltage Regulators
To PWM
R
C
O1
O1
O1
O1
inserted)
.