STEVAL-ISA014V1 STMicroelectronics, STEVAL-ISA014V1 Datasheet - Page 11

• Manufacturer Part Number: STEVAL-ISA014V1
• Description: EVAL BOARD TRAVEL ADAPTOR 3.6W
• Manufacturer: STMicroelectronics
• Series: VIPER™r
• Type: AC/DC Switching Convertersr

Specifications of STEVAL-ISA014V1

• Design Resources: STEVAL-ISA014V1 Gerber Files STEVAL-ISA014V1 Schematic STEVAL-ISA014V1 Bill of Materials
• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Power - Output: 3.6W
• Voltage - Output: 6V
• Current - Output: 600mA
• Voltage - Input: 85 ~ 264VAC
• Regulator Topology: Flyback
• Frequency - Switching: 60kHz
• Board Type: Fully Populated
• Utilized Ic / Part: VIPer12A
• Input Voltage: 86 V to 264 V
• Output Voltage: 6 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Silicon Core Number: VIPer12A
• Kit Application Type: Reference Design
• Application Sub Type: Travel Adapter
• Kit Contents: VIPer12A Travel Adapter
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: VIPer12A
• Other names: 497-5084

VIPER12A-E
7
Startup sequence
Figure 7.
This device includes a high voltage start up current source connected on the drain of the
device. As soon as a voltage is applied on the input of the converter, this start up current
source is activated as long as V
current source is switched off and the device begins to operate by turning on and off its main
power MOSFET. As the FB pin does not receive any current from the optocoupler, the
device operates at full current capacity and the output voltage rises until reaching the
regulation point where the secondary loop begins to send a current in the optocoupler. At
this point, the converter enters a regulated operation where the FB pin receives the amount
of current needed to deliver the right power on secondary side.
This sequence is shown in
consumes some energy from the V
continuous supply. If the value of this capacitor is too low, the start up phase is terminated
before receiving any energy from the auxiliary winding and the converter never starts up.
This is illustrated also in the same figure in dashed lines.
Startup sequence
Figure
Doc ID 11977 Rev 2
DD
7. Note that during the real starting phase t
DD
is lower than V
capacitor, waiting for the auxiliary winding to provide a
DDon
. When reaching V
Startup sequence
DDon
ss
, the start up
, the device
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