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Evaluation Board for Active EMI Filters
The QPI-X-EVAL1 is an easy to use evaluation
board for testing the QPI family of active EMI
filters. The evaluation board includes a mounted
QPI, capacitors, optional RY resistor and screw
terminals for electrical connections.
When using the evaluation board, pay special
attention to wiring and grounding. Wires should be
kept as short as possible and positioned to minimize
radiated pick up around the QPI. Refer to
Figure 1
below and the QPI-AN1 application note for the
proper measurement set up.
Figure 2
shows the schematic of the QPI-X-EVAL1.
Note that resistor RY is included with the evaluation
board for use with non-resonant mode converters. To
ensure the best results, make sure that the QPI shield
connection is as close as possible to the common point
of the bypass Y-capacitors and shield plane under the
converters on the system board.
Figure 3
shows the component locations on the EVAL
board PCB.
Filter performance in the application is highly
dependent on several factors and cannot be
extrapolated from insertion loss curves alone. Final
noise performance is a complex function of filter
elements, equipment grounding and noise source
impedances, which vary in magnitude and phase over
the frequency spectrum of interest.
Designers should be aware that to select and qualify
an EMI filter for conducted noise, they must test the
filter in their product under the set up and conditions
specified in the applicable EMI standards. Measurements
should be made in consultation with in-house
compliance testing or an independent EMI test facility.
Check www.picorpower.com for data sheets,
application notes and additional product information.
LISN
BUS+
QPI+
C
IN
VIN+
VOUT+
BUS
SUPPLY
BUS-
LISN
QPI
SHIELD
CONVERTER
QPI-
C
1
C
2
VIN-
VOUT-
C
3
C
4
Optional GND
Connection
LISN Ground Plane
RY
Figure 1
- Spectrum Analyzer Test Setup for the evaluation board (QPI and Converter 5mm above LISN Ground Plane)
Picor Corporation 鈥?www.picorpower.com
QPI-X-EVAL1 Data Sheet Rev. 1.2
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