Si9113DB
Vishay Siliconix
Si9113 Demonstration Board
FEATURES
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ISDN-NT Input Voltage Range 28 V to 99 V
Non-Polar Input
3.3-V/120-mA, 40-V/12-mA Outputs With Up To 80% Efficiency
Up to 68% Efficiency at 80-mW Load
40 V Isolated By 3 kV From Input And 3.3-V Output 鈥?Si9113D1
3.3 V, 40 V Isolated By 1.5 kV From Input/Each Other 鈥?Si9113D2
Current Mode Control, 0.6-V Fast Over-Current Protection
Max 50% Duty Cycle Operation
1.3-MHz Error Amp
Soft-Start
<10-mA Supply Current for +V
IN
<18 V
Programmed Start/Stop
Internal Start-Up Circuit
Power_Good Output
DESCRIPTION
As discussed in application note, AN728, the Si9113 power
supply controller is an ideal choice for ISDN terminal
equipment, where high efficiency at a low power level is one of
most important criteria. Therefore, Vishay Siliconix has
developed versions of a dual output flyback application
demonstration boards, the Si9113D1 and the Si9113D2, which
use different regulation schemes. These readily available
demo boards are configured to deliver approximately 800 mW
at 3.3-V, and40-V. These outputs and can be easily modified
for other output voltages at approximately same power level.
The flyback converters are designed to operate from a wide
input voltage range of 28 V to 99 V and are polarity protected
by a diode bridge. The Si9113D1 and Si9113D2, both operate
at 20-kHz switching frequency to achieve the best possible
efficiency. The transformer is selected to be slightly larger in
this application so that the same area product would be good
enough for an even lower window utilization factor (w.u.f.)
transformer in order to meet the stringent requirements of
clearance and creepage distances.
The Si9113D1 senses and tightly regulates the main output
V
OUT1
(3.3 V), which has the common ground as input and the
secondary output V
OUT2
(40 V) is regulated to within
$10%
at
10% to100% load range, including the set point accuracy.
Correspondingly. the transformer must be specified with tight
tolerance to achieve the given set point accuracy. The 40-V
output is isolated from both the input and 3.3-V output by
minimum 3 kV
rms
isolation.
The Si9113D2 uses the auxiliary output (V
CC
bootstrap
winding) for sensing. Both V
OUT1
(3.3 V) and V
OUT2
(40 V)
follow the auxiliary output, residing on one core and sharing the
same flux. Both the outputs are isolated from the input as well
as from each other by 1.5 kV and moderately regulated to
$5%.
Each demonstration board uses all surface mount
components except the high voltage electrolyte capacitor and
are fully assembled and tested for quick evaluation. Test points
are provided for the power_good signal and the closed loop
response measurement.
Included in this document are the Bill-Of-Materials,
Schematics, PCB Layout of the Demo Boards and actual
waveforms/graphs.
The demonstration board layout is available in Gerber file format. Please contact your Vishay Siliconix sales representative or
distributor for a copy.
ORDERING INFORMATION:
Si9113D1鈥?/div>
V
OUT1
(3.3 V) Tightly regulated, non-isolated
V
OUT2
(40 V) Loosely regulated, 3 kV isolated
Si9113D2鈥?/div>
V
OUT1
(3.3 V) Moderately regulated, 1.5 kV isolated
V
OUT2
(40 V) Moderately regulated, 1.5 kV isolated
Document Number: 71117
29-Feb-00
www.siliconix.com
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FaxBack 408-970-5600
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