EVALA5973D STMicroelectronics, EVALA5973D Datasheet - Page 14
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EVALA5973D
Manufacturer Part Number
EVALA5973D
Description
Power Management Modules & Development Tools EVAL BOARD A5973D Auto Grade
Manufacturer
STMicroelectronics
Type
DC/DC Switching Converters, Regulators & Controllersr
Datasheet
1.EVALA5973D.pdf
(30 pages)
Specifications of EVALA5973D
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
2.5 A
Dimensions
23 mm x 20 mm
For Use With/related Products
AN1518
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
PWM comparator
14/30
Where K is equal to 0.076. Therefore the PWM gain is also equal to:
Equation 14
This means that even if the input voltage changes, the error amplifier does not change its
value to keep the loop in regulation, thus ensuring a better line regulation and line transient
response.
In summary, the Open Loop Gain can be expressed as:
Equation 15
Example:
The gain and phase bode diagrams are plotted respectively in
Figure 11. Module plot
Considering R
If L = 22 µH, C
Finally R
F
F
F
F
F
P1
P2
Z1
PLC
0
= 19.89 kHz
1
= 2.68 kHz
= 9 Hz
= 256 kHz
= 3.39 kHz
= 5.6 kΩ and R
C
OUT
= 2.7 kΩ , C
= 100 µF and ESR = 80 mΩ , the poles and zeroes of A
G s ( )
=
2
= 3.3 kΩ .
C
G
PWM
= 22 nF and C
G
PWM
s ( )
s ( )
•
------------------- -
R
=
1
R
+
--- -
K
1
2
R
P
=
2
= 220 pF, the poles and zeroes of A
•
const
A
O
s ( )
•
A
LC
Figure 11
s ( )
and
Figure
LC
become:
AN1518
12.
0
are: