STEVAL-ISA019V2 STMicroelectronics, STEVAL-ISA019V2 Datasheet - Page 18

• Manufacturer Part Number: STEVAL-ISA019V2
• Description: BOARD EVAL SMPS L6565 3PHASE APP
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of STEVAL-ISA019V2

• Mfg Application Notes: L6565/STC04IE170HV AppNote
• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Power - Output: 80W
• Voltage - Output: 24V
• Current - Output: 3.33A
• Voltage - Input: 250 ~ 850V
• Regulator Topology: Flyback
• Board Type: Fully Populated
• Utilized Ic / Part: L6565, STC04IE170HV
• Input Voltage: 250 V to 850 V
• Output Voltage: 24 V
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: L6565, STC04IE170HV
• Other names: 497-6339

6
18/34
Frequency response and loop compensation
Frequency response and loop compensation
The transfer function in the complex frequency domain of the discontinuous current mode
(DCM) flyback converter with L6565 driver is given by:
Equation 36
The parameters and values are listed in
Table 3.
It is worth noting that the transfer function has one pole and one zero on the left half plane
and an additional zero on the right half plane. The RHP zero is very difficult, if not
impossible, to compensate and therefore must be kept well beyond the closed-loop
bandwidth. As a result, the transient response of such a system will not be extremely fast.
Poles and zeros are given in
Equation 37
A good line and load regulation implies a high DC gain, thus the open loop gain should have
a pole at the origin. Normally in this case we need a feedback network like the one in
Figure
G
1
s ( )
9.
R
Parameter
=
out
---------------------- -
V
Transfer function main parameters
D
=V
ESR
C
V
R
comp s ( )
L
max
n
out
out s ( )
p
S
out
/I
out
=
n R
------------------------------------------------------
2 R
•
•
f
p
out
=
S
Equation 37
•
25Hz f
Doc ID 13127 Rev 4
•
(
(
1
1 D
Primary/secondary turn-ratio
Electrolytic series resistance
+
–
;
D
Z1
Maximum duty-cycle
max
Output capacitance
Primary inductance
max
Sensing resistor
=
Description
)
Table
Output load
3.5 10
)
and
•
(
-------------------------------------------------------------------------------------------------------------------------------
•
1
+
Equation
3.
s C
5
Hz f
•
;
out
Z2
=
•
38:
ESR
5 10
1
•
+
) 1 s
s
⎛
⎜
⎝
3
•
Hz
C
-----------------------
1
–
out
+
•
D
R
-------------------------------------------------
n
max
out
2
R
1.56 mH
out
16 mΩ
Value
0.8 Ω
7.2 Ω
2 mF
L
0.5
10
p
(
1 D
D
max
–
max
AN2495
)
2
⎞
⎟
⎠