STEVAL-ISA062V1 STMicroelectronics, STEVAL-ISA062V1 Datasheet - Page 15
![BOARD EVAL BASED ON VIPER17](/photos/9/14/91480/steval-isa062v1_sml.jpg)
STEVAL-ISA062V1
Manufacturer Part Number
STEVAL-ISA062V1
Description
BOARD EVAL BASED ON VIPER17
Manufacturer
STMicroelectronics
Series
VIPer™ plusr
Specifications of STEVAL-ISA062V1
Main Purpose
AC/DC, Primary Side
Outputs And Type
2, Isolated
Power - Output
5.5W
Voltage - Output
5V, 12V
Current - Output
500mA, 250mA
Voltage - Input
85 ~ 264VAC
Regulator Topology
Flyback
Frequency - Switching
115kHz
Board Type
Fully Populated
Utilized Ic / Part
VIPer17
Input Voltage
85 VAC to 264 VAC
Output Voltage
5 V, 12 V
Maximum Operating Temperature
+ 105 C
Minimum Operating Temperature
0 C
Product
Power Management Modules
Supply Current
0.5 A, 0.25 A
Silicon Manufacturer
ST Micro
Silicon Core Number
VIPER17
Kit Application Type
Power Management
Application Sub Type
SMPS
Kit Contents
Board
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
For Use With/related Products
VIPER17
Other names
497-9007
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
STEVAL-ISA062V1
Manufacturer:
STMicroelectronics
Quantity:
1
VIPER17
7.3
Power-up and soft-start up
If the input voltage rises up till the device start threshold, V
begins to grow due to the I
high voltage start up circuit. If the V
page
See
The IC is powered by the energy stored in the capacitor on the VDD pin, C
the self-supply circuit (typically an auxiliary winding of the transformer and a steering diode)
develops a voltage high enough to sustain the operation.
C
value higher than V
switching operation before the controller receives any energy from the auxiliary winding.
The following formula can be used for the V
Equation 1
The t
estimated by applicator according to the output stage configurations (transformer, output
capacitances, etc.).
During the converter start up time, the drain current limitation is progressively increased to
the maximum value. In this way the stress on the secondary diode is considerably reduced.
It also helps to prevent transformer saturation. The soft-start time lasts 8.5 ms and the
feature is implemented for every attempt of start up converter or after a fault.
Figure 22. I
VDD
Figure 23 on page
SSaux
6) the power MOSFET starts switching and the HV current generator is turned OFF.
capacitor must be sized enough to avoid fast discharge and keep the needed voltage
is the time needed for the steady state of the auxiliary voltage. This time is
I
DDch
DD
V
(-3 mA)
DRAIN
V
V
V
V
V
V
current during start-up and burst mode
FBbm
DDoff
V
FBolp
I
I
I
DDon
FBlin
DD
DD1
DD0
DD
START- UP
FB
DDoff
16.
threshold. In fact, a too low capacitance value could terminate the
DDch
NORMAL MODE
Doc ID 14419 Rev 7
current (see
C
DD
VDD
voltage reaches V
=
----------------------------------------
V
I
DD
DDch
DDon
Table 7 on page
capacitor calculation:
×
–
BURST MODE
t
V
SSaux
DDoff
DDon
DRAIN_START
6) coming from the internal
threshold (see
Operation descriptions
, the V
NORMAL MODE
VDD
t
t
t
t
V
FBbmhys
Table 7 on
DD
, until when
voltage
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