STEVAL-ISA011V1 STMicroelectronics, STEVAL-ISA011V1 Datasheet - Page 9

• Manufacturer Part Number: STEVAL-ISA011V1
• Description: BOARD EVAL VIPER12A LP AC/DC
• Manufacturer: STMicroelectronics
• Series: VIPER™r
• Type: AC/DC Switching Convertersr

Specifications of STEVAL-ISA011V1

• Design Resources: STEVAL-ISA011V1 Gerber Files STEVAL-ISA011V1 Schematic STEVAL-ISA011V1 Bill of Materials
• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Power - Output: 4.1W
• Voltage - Output: 4.5V
• Current - Output: 900mA
• Voltage - Input: 88 ~ 265VAC
• Regulator Topology: Flyback
• Frequency - Switching: 60kHz
• Board Type: Fully Populated
• Utilized Ic / Part: VIPer12A
• Input Voltage: 88 V to 265 V
• Output Voltage: 4.5 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Silicon Core Number: VIPER12ADIP-E
• Kit Application Type: Power Management - Voltage Regulator
• Application Sub Type: AC / DC Adapter
• Kit Contents: Board
• Rohs Compliant: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: VIPer12A
• Other names: 497-6413; STEVAL-ISA011V1

AN2272 - Application Note
1.2.1
D
Equation 11
Equation 12
11
The average current flowing through D
expressed as:
Where,
I
I
D
For one output flyback, I
as the primary peak current multiplied by the turns ratio.
Note: This formula applies only to DCM operation.
D
Where,
P
V
I
r
Note: The formula and the correct values for V
Current and Power Dissipation
DRMS
PKS
D(avg)
dD
lossD
dD
s_cond
11
= dynamic resistance.
power dissipation is calculated as follows:
= drop voltage (when the diode is forward-biased),
= peak current at secondary winding, and
= current root mean square,
= diode power dissipation,
= diode average current, and
= conduction duty cycle of the secondary diode.
P
PKS
los sD
I
(peak current at the secondary winding) can be calculated
DRMS
=
Rev. 1
V
dD
=
I
I
11
PKS
D avg
is the output current while the I
D
-------------------- -
+
dD
r
s cond
dD
–
3
and r
STEVAL-ISA011V1 Board Design
I
2
DRMS
dD
are in the diode datasheets.
DRMS
value is
9/33