STEVAL-ISA019V2 STMicroelectronics, STEVAL-ISA019V2 Datasheet - Page 19

• 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

AN2495
Figure 9.
Its transfer function, which comprises a pole at the origin and a zero-pole pair, is given by:
Equation 38
The task of the control loop design is then to determine the transfer function G
that the resulting closed-loop system is stable and performs well in terms of dynamic
response, and line and load regulation. It is well known that the characteristics of the closed-
loop system can be inferred from its open loop transfer function properties, that is G(s) =
G
Frequency response requirements are summarized below:
1.
2.
3.
First choose a typical value for R
From the L6565 datasheet we know that I
and can obtain:
Equation 39
R
parallel to the photodiode.
24
1
(s) · G
= 1.5 kΩ is a good choice. It is good practice to put a 3.3 kΩ resistor (R
Optimum dynamic performance requires a large gain bandwidth, that is the open-loop
cross-over frequency f
Phase margin ϕ
ensures fast transient response with very little ringing. Sometimes this is not enough
and so phase shift should be lower than 180° at any frequency below f
phase shift over 180° would result in a conditionally stable system.
Good load and line regulation implies a high DC gain (this requirement is ensured by
the feedback network, whose transfer function has a pole at the origin).
2
(s).
Converter feedback network
G
2
s ( )
R
m
B
comprised between 45° and 90° is used as a design guideline. This
=
=
v
-----------------------
R
V
comp
24
C
out
to be typically chosen equal to f
<
s ( )
Doc ID 13127 Rev 4
s ( )
V
-------------------------------------------------------
out
L
=
= R
–
CTR
----------------------------------------------- -
(
22
V
I
comp
ref
= 2.7 kΩ.
R
max
comp
B
–
R
V
Frequency response and loop compensation
•
H
diode
R
C
= 5 mA (source current) and R
COMP
F
)
=
24V 3.5V
---------------------------- -
•
1
-- -
s
5mA
•
–
------------------------------------------------- -
1
1
+
+
sw
sR
s R
(
=
/5 (f
COMP
4.1kΩ
H
+
c
R
= 10 kHz).
C
F
comp
)C
F
23
C
, because a
comp
= 3.3 kΩ) in
2
(s) to ensure
= 15 kΩ.
19/34