EVALA5973AD STMicroelectronics, EVALA5973AD Datasheet - Page 14

• Manufacturer Part Number: EVALA5973AD
• Description: Power Management Modules & Development Tools EVAL BOARD A5973AD Auto Grade
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EVALA5973AD

• 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: