STEVAL-ISA019V2 STMicroelectronics, STEVAL-ISA019V2 Datasheet - Page 16

• 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

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Output circuit design
Output circuit design
To choose the output capacitor, the series resistance of the electrolytic capacitor must be
defined.
It is well known that the main cause of the output ripple is the series resistance of the
electrolytic capacitor, known as ESR, while the capacitive ripple is absolutely negligible.
Therefore, with a known secondary side peak current of 16 A and imposing a resistive ripple
equal to 2% (0.48 V), we have:
Equation 30
Using very low ESR output capacitances, from the catalogue we get the equation
ESR*C=32e
Equation 31
To obtain some margin and better thermal spread, the final choice is to use two 680 µF
capacitors in parallel.
From Kirchoff’s voltage law we can calculate the maximum voltage stress on the output
diode:
Equation 32
Finally, adding a 10% margin, the STPS20120D has been selected.
-6
s from which:
V
off diode
Doc ID 13127 Rev 4
–
ESR
C
out
<
>
=
V
---------------- -
32 10
----------------------- -
ripple
I
ESR
V
SP
•
out
=
+
–
6
N
------ - V
N
0.48
---------- -
=
16
S
P
1066μF
•
=
inmax
0.03Ω
=
109V
AN2495