STEVAL-ISA011V1 STMicroelectronics, STEVAL-ISA011V1 Datasheet - Page 11

• 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
1.2.3
C
The output capacitor selection (C
depends on the output voltage ripple specification ( V
rate of the capacitor itself. The output voltage ripple is mainly due to the Equivalent Series
Resistor (ESR), so we have to select a capacitor with an ESR lower than the maximum
allowed ESR value:
Equation 17
Where,
ESR
I
The AC component of the current flowing through the output diode is also that of the current
flowing through the capacitor. The C11 capacitor current rate has to be higher than the
calculated current, which is expressed as:
Equation 18
Where,
I
I
I
The MBZ Type 1500 F 10V by RUBYCON capacitor was selected for this application.
PKS
CAPRMS
DRMS
O
V
11
O
= output current.
MAX
= output voltage ripple, and
= peak current at secondary winding.
Output Capacitor Selection
= diode current root mean square, and
= capacitor current root mean square,
= maximum allowed ESR rating,
11
I
CAPRMS
, see
Rev. 1
ESR
STEVAL-ISA011V1 Schematic on page 30
MAX
=
I
2
=
DRMS
-------------- -
I
PKS
V
O
–
O
I
2
= 300mV), and the ripple current
O
STEVAL-ISA011V1 Board Design
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