EVALA5970D STMicroelectronics, EVALA5970D Datasheet - Page 12

• Manufacturer Part Number: EVALA5970D
• Description: Power Management Modules & Development Tools EVAL BOARD A5970D Auto Grade
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EVALA5970D

• Input Voltage: 4.4 V to 36 V
• Output Voltage: 1.235 V to 35 V
• Board Size: 23 mm x 20 mm
• Product: Power Management Modules
• Supply Current: 1 A
• Dimensions: 23 mm x 20 mm
• For Use With/related Products: AN1330
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Closing the loop
4
4.1
12/31
Closing the loop
Figure 9.
Error amplifier and compensation network
The output L-C filter of a step-down converter contributes with 180 degrees phase shift in
the control loop. For this reason a compensation network between the COMP pin and
GROUND is added. The simplest compensation network together with the equivalent circuit
of the error amplifier are shown in
open loop gain. C
noise of the COMP pin.
The transfer function of the error amplifier and its compensation network is:
Equation 2
Where A
A
vo
0
s ( )
= G
Block diagram of the loop
=
m
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
s
· R
2
P
•
does not significantly affect system stability but it is useful to reduce the
o
R
0
•
(
C
0
+
C
p
) R
•
Figure
c
•
A
C
V0
10. R
c
+
•
s
(
•
1
C
(
+
R
and C
s
0
•
•
R
C
c
c
C
•
+
C
introduce a pole and a zero in the
R
c
0
)
•
(
C
0
+
C
p
)
+
R
c
•
C
c
)
+
1
AN1330