Picor Corporation · picorpower.com QPI-12 Rev 2.0, Page 1 of 12
QPI-12
QUIETPOWER
7A V•I Chip™ EMI Filter SIP
Description:
The QPI-12 EMI filter is specifically designed to attenuate
conducted common-mode (CM) and differential-mode (DM)
noise of Vicor’s V•I Chip™ products, such as the PRM, VTM
and BCM converters, to comply with the CISPR22 standard
requirements for conducted noise measurements. The filter is
designed to operate up to 80 Vdc, 100 Vdc surge, and
supports 7A loads up to 85°C (TA) without de-rating.
Designed for the telecom bus range, the V•I Chip™ EMI Filter
supports the PICMG® 3.0 specification for filtering system
boards to the EN55022 Class B limits.
Figure 1 - QPI-12LZ (~1/2 in2 area)
Features:
>40 dB CM attenuation at 1 MHz (50Ω)
>70 dB DM attenuation at 1 MHz (50Ω)
80 Vdc (max input)
100 Vdc surge 100 ms
1,500 Vdc hipot hold off to shield plane
7 A rating
12.9 x 25.3 x 5.0 mm Lidded SiP (System-in-Package)
12.4 x 24.9 x 3.4 mm Open-frame SiP
Low profile LGA package
-40° to +125°C Ambient temperature (see Figure 6)
Efficiency >99%
TÜV Certified
Applications
V·I Chip™ input EMI filter
Telecom and ATCA boards
Typical Applications:
Figure 2 – Typical QPI-12 application schematic with Vicor’s PRM and VTM modules. (1)
Figure 3 – Typical QPI-12 application schematic with Vicor’s BCM modules. (1)
Note 1: CB1 capacitor, referenced in all schematics, is a 47uF electrolytic; United Chemi-Con EMVE101ARA470MKE0S or equivalent.
CY1 to CY4, referenced in all schematics, are 4.7nF hi-voltage safety capacitors; Vishay VY1472M63Y5UQ63V0 or equivalent.
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QPI-12
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Absolute Maximum Ratings – Exceeding these parameters may result in permanent damage to the product.
Input Voltage, BUS+ to BUS-, continuous
-80 to 80 Vdc
Input Voltage, BUS+ to BUS-, 100ms transient
-100 to 100 Vdc
BUS+/ BUS- to Shield pads, hi-pot
-1500 to 1500 Vdc
Input to output current, continuous @ 25°C TA
7 Adc
Power dissipation, @ 85°C TA, 7A(2)
1.85 W
Operating temperature - TA
-40 to 125 °C
Thermal resistance(2) - R
J-A, using PCB layout in Figure 25
30 °C/W
Thermal resistance(2) - R
J-PCB
18 °C/W
Storage temperature, JEDEC Standard J-STD-033B
-55 to 125 °C
Reflow temperature, 20 s exposure
245 °C
ESD, Human body model (HBM)
-2000 to 2000 V
Electrical Characteristics – Parameter limits apply over the operating temp. range, unless otherwise noted.
Parameter
Notes
Min
Typ
Max
Units
BUS+ to BUS- input range
Measured at 7 A, 85°C ambient temperature(2)
80
Vdc
BUS+ to QPI+ voltage drop
Measured at 7 A, 85°C ambient temperature(2)
130
mVdc
BUS- to QPI- voltage drop
Measured at 7 A, 85°C ambient temperature(2)
130
mVdc
Common mode attenuation
VBUS = 48 V, Frequency = 1.0 MHz, line impedance = 50Ω
40
dB
Differential mode attenuation
VBUS = 48 V, Frequency = 1.0 MHz, line impedance = 50Ω
70
dB
Input bias current at 80 V
Input current from BUS+ to BUS-
10
uA
Note 2: See Figure 6 for the current de-rating curve.
Pad Descriptions
Pad Number
Name
Description
LGA Pattern (Top View)
8, 9
BUS+
Positive bus potential
1, 10
BUS-
Negative bus potential
6, 7
QPI+
Positive input to the converter
4, 5
QPI-
Negative input to the converter
2, 3
Shield
Shield connects to the system chassis or to a
safety ground.
Ordering Information
Part Number
Description
QPI-12LZ(3)
QPI-12 LGA Package, RoHS Compliant
QPI-12LZ-01
QPI-12 LGA Package, RoHS Compliant, Open Frame Package
Note 3: QPI-12LZ is a non-hermetically sealed package. Please read the “Post Solder Cleaning” section on page 11.
QPI-12 Evaluation Boards
Part #
Description:
QPI-12-CB1
A QPI-12LZ mounted on a carrier board that can hold either a stand-alone BCM or a paired PRM/VTM
evaluation board available from Vicor.
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QPI-12
QUIETPOWER
Applications Information
EMI Sources
Many of the components in today’s power conversion
modules are sources of high-frequency EMI noise generation.
Diodes, high-frequency switching devices, transformers and
inductors, and circuit layouts passing high dv/dt or di/dt
signals are all potential sources of EMI.
EMI is propagated either by radiated or conductive means.
Radiated EMI can be sourced from these components as well
as by circuit loops that act like antennas and broadcast the
noise signals to neighboring circuit paths. This also means
that these loops can act as receivers of a broadcasted signal.
This radiated EMI noise can be reduced by proper circuit
layout and by shielding potential sources of EMI transmission.
There are two basic forms of conducted EMI that typically
need to be filtered; namely common-mode (CM) and
differential-mode (DM) EMI. Differential-mode resides in the
normal power loop of a power source and its load; where the
signal travels from the source to the load and then returns to
the source. Common-mode is a signal that travels through
both leads of the source and is returned to earth via parasitic
pathways, either capacitively or inductively coupled.
Figure 10 to Figure 17 are the resulting EMI plots of the total
noise, both common and differential mode, of Vicor’s
PRM/VTM and BCM evaluation modules, under various loads,
after filtering by the QPI-12LZ. The red and blue traces
represent the positive and negative branches of total noise,
as measured using an industry standard LISN setup, shown in
Figures 4 and 5. The PRM and VTM evaluation boards are
mounted to a Picor QPI-12-CB1 board for testing. The QPI-
12-CB1 carrier is designed to accept both the PRM/VTM
combination of evaluation boards, as well as the stand-alone
BCM evaluation board.
Differential-mode EMI is typically larger in magnitude than
common-mode, since common-mode is created by the
physical imbalances in the differential loop path. Reducing
differential EMI will cause a reduction in common-mode EMI.
EMI Filtering
The basic premise of filtering EMI is to insert a high-
impedance, at the EMI’s base frequency, in both the
differential and common-mode paths as it returns to the
power source.
Passive filters use common-mode chokes and “Y” capacitors
to filter out common-mode EMI. These chokes are designed
to present a high-impedance at the EMI frequency in series
with the return path, and a low impedance path to the earth
signal via the “Y” caps. This network will force the EMI signals
to re-circulate within a confined area and not to propagate to
the outside world. Often two common-mode networks are
required to filter EMI within the frequency span required to
pass the EN55022 class B limits.
The other component of the passive filter is the differential
LC network. Again, the inductor is chosen such that it will
present a high-impedance in the differential EMI loop at the
EMI’s base frequency. The differential capacitor will then
shunt the EMI back to its source. The QPI-12 was specifically
designed to work with higher switching frequency converters
like Vicor’s V•I Chip™ products; PRM, VTM and BCM modules;
as well as their newer VI Brick™ product series.
Figure 4 - Open-frame EMI test setup using the QPI-12-CB1 carrier board with V•I Chip™ evaluation boards.
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QPI-12
QUIETPOWER
Figure 5 - Base-plate EMI test setup using the QPI-12-CB1 carrier board with V•I Chip™ evaluation boards.
EMI Management
The more effectively EMI is managed at the source, namely
the power converter, the less EMI attenuation the filter will
have to do. The addition of “Y” capacitors to the input and
output power nodes of the converter will help to limit the
amount of EMI that propagates to the input source.
There are two basic topologies for the connection of the re-
circulating “Y” capacitors. In Figure 4 the open-frame
topology is shown in Picor’s EMI test setup. The “Y”
capacitors (CY1 to CY4) re-circulate the EMI signals between
the positive input and output, and the negative input and
output of the power conversion stage.
Figure 5 shows the base-plate topology of re-circulating “Y”
caps. Here, CY5 to CY10 are connected to each power node
of the PRM and VTM, and then are commoned together on a
copper shield plane created under the converter. The
addition of the copper shield plane helps in the containment
of the radiated EMI, converting it back to conducted EMI and
shunting it back to its source.
Both of these topologies work well with the PRM/VTM
combination shown above in attenuating noise levels well
below class B EMI limits.
Current De-Rating: mounted to QPI-12-CB1 evaluation board.
Figure 6 - Current de-rating over ambient temperature range.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
-40 -20 020 40 60 80 100 120
Load Current (A)
Ambient Temperature (°C)
QPI-12LZ-01
QPI-12LZ
limited by TJMAX =
140 °C
limited
by
TPCBMAX =
125 °C
Picor Corporation · picorpower.com QPI-12 Rev 2.0, Page 5 of 12
QPI-12
QUIETPOWER
QPI Insertion Loss Measurements
Figure 7 - Attenuation curves into a 50Ω line impedance, bias from a 48V bus.
QPI Insertion Loss Equation:
QPI Insertion Loss Test Circuits
Figure 8 – Test Set-up to measure Differential Mode EMI currents in Figure 7.
Figure 9 - Test Set-up to measure Common Mode EMI currents in Figure 7.
0
10
20
30
40
50
60
70
80
90
0.1 1 10
Attenuation [dB]
Frequency [MHz]
QPI-12 Differential
QPI-12 Common
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QPI-12
QUIETPOWER
Attenuation Plots:
QPI-12 with PRM P048F048T24AL-CB and various VTM modules, connected in Base-plate configuration, as shown in Figure 4.
Figure 10 - VTM V048F030T070-CB with 160W Load.
Figure 11 - VTM V048F120T025-CB with 180W Load.
Figure 12 - VTM V048F240T012-CB with 172W Output Load.
Figure 13 - VTM V048F480T006-CB with 153W Load.
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QPI-12
QUIETPOWER
QPI-12 with various BCM modules, connected in open frame configuration, as shown in Figure 18.
Figure 14 - BCM B048F030T21-EB with 160W Load.
Figure 15 - BCM B048F120T30-EB with 180W Load.
Figure 16 - BCM B048F240T30-EB with 172W Load.
Figure 17 - BCM B048F480T30-EB with 152W Load.
The red and blue traces in Figure 10 through Figure 17 are the measurements of total EMI, in both the positive and negative
branches. The test setups shown in Figure 4 and Figure 5 are representative of measuring the positive branch of the total EMI for
the unit under test.
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Converter Output Grounding: Recommended configurations.
Figure 18 – BCM converter in open-frame configuration with the output connected to chassis/earth.
Figure 19 - PRM/VTM in open-frame configuration with the output connected to the chassis/earth.
When using the QPI-12 with a Vicor PRM/VTM or BCM, in a
power system that requires the converter’s output to be
connected to chassis/earth, Picor recommends using the
open-frame configuration of “Y” capacitors, shown in Figure
18, to re-circulate EMI currents. A base-plate configuration
could also be used with a slight decrease in EMI attenuation,
but with peaks well below class B limits.
The plot in Figure 20 is of a B048F120T30, with a 125W load,
with the output ground connected to the chassis. When
using the open-frame configuration of “Y” caps, the EMI
shield plane is not used by the “Y” capacitors for re-
circulating EMI currents.
This configuration would also be recommended for a QPI-12
with a PRM/VTM pair, configured as shown in Figure 2.
The QPI-12 is not designed to be used in parallel with another
QPI-12 to achieve a higher current rating, but it can be used
multiple times within a system design.
Figure 20 – Total noise plot of BCM with its output connected
to chassis, as shown in Figure 18, 125W load.
Picor Corporation · picorpower.com QPI-12 Rev 2.0, Page 9 of 12
QPI-12
QUIETPOWER
Mechanicals
Figure 21 - Lidded Package Dimensions, tolerance of ±0.004”
Figure 22 - Open-frame Package dimensions, tolerance of ±0.004”. Pick and Place from label center.
QPI-12 Mechanical Data
Datum
Units
QPI-12LZ
QPI-12LZ-01
Notes
FITS
Failure/Billion Hrs.
16
16
FITS based on the BellCore Standard TR-332
MTBF
Million Hrs.
62.5
62.5
MTBFs based on the BellCore Standard TR-332
Weight
grams
2.4
2.075
MSL
3
3
Peak reflow
Temperature
°C/20 seconds
245
245
IPC/JEDEC J-STD-020D
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QPI-12
QUIETPOWER
Pad and Stencil Definitions:
Figure 23 - Bottom view of open-frame (OF) and lidded (LID) products. (All dimensions are in inches.)
Figure 24 - Recommended receptor and stencil patterns. (All dimensions are in inches.)
Stencil definition is based on a 6mil stencil thickness, 80% of LGA pad area coverage. LGA Package dimensions are for both the Open-
Frame and Lidded versions of the QPI-12.
Picor Corporation · picorpower.com QPI-12 Rev 2.0, Page 11 of 12
QPI-12
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QPI-12 PCB Layout Recommendations:
Figure 25 - 3D view of paralleling planes underneath the QPI-12.
The filtering performance of the QPI-12 is sensitive to
capacitive coupling between its input and output pins.
Parasitic plane capacitance must be kept below 1 pico-Farad
between inputs and outputs using the layout shown above
and the recommendations described below to achieve
maximum conducted EMI performance.
To avoid capacitive coupling between input and output pins,
there should not be any planes or large traces that run under
both input and output pins, such as a ground plane or power
plane. For example, if there are two signal planes or large
traces where one trace runs under the input pins, and the
other under the output pins, and both planes over lap in
another area, they will cause capacitive coupling between
input and output pins. Also, planes that run under both input
and outputs pins, but do not cross, can cause capacitive
coupling if they are capacitively by-passed together. Figure 25
shows the recommended pcb layout on a 2 layer board. Here,
the top layer planes are duplicated on the bottom layer so
that there can be no overlapping of input and output planes.
This method can be used for boards of greater layer count.
Post Solder Cleaning
Picor’s LZ version QP SIPs are not hermetically sealed and
must not be exposed to liquid, including but not limited to
cleaning solvents, aqueous washing solutions or pressurized
sprays. When soldering, it is recommended that no-clean flux
solder be used, as this will ensure that potentially corrosive
mobile ions will not remain on, around, or under the module
following the soldering process. For applications where the
end product must be cleaned in a liquid solvent, Picor
recommends using the QPI-12LZ-01, open-frame version of
the EMI filter.
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QPI-12
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Warranty
Vicor products are guaranteed for two years from date of shipment against defects in material or workmanship when in
normal use and service. This warranty does not extend to products subjected to misuse, accident, or improper
application or maintenance. Vicor shall not be liable for collateral or consequential damage. This warranty is extended to
the original purchaser only.
EXCEPT FOR THE FOREGOING EXPRESS WARRANTY, VICOR MAKES NO WARRANTY, EXPRESS OR LIMITED, INCLUDING,
BUT NOT LIMITED TO, THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Vicor will repair or replace defective products in accordance with its own best judgment. For service under this
warranty, the buyer must contact Vicor to obtain a Return Material Authorization (RMA) number and shipping
instructions. Products returned without prior authorization will be returned to the buyer. The buyer will pay all charges
incurred in returning the product to the factory. Vicor will pay all reshipment charges if the product was defective within
the terms of this warranty.
Information published by Vicor has been carefully checked and is believed to be accurate; however, no responsibility is
assumed for inaccuracies. Vicor reserves the right to make changes to any products without further notice to improve
reliability, function, or design. Vicor does not assume any liability arising out of the application or use of any product or
circuit; neither does it convey any license under its patent rights nor the rights of others. Vicor general policy does not
recommend the use of its components in life support applications wherein a failure or malfunction may directly threaten
life or injury. Per Vicor Terms and Conditions of Sale, the user of Vicor components in life support applications assumes
all risks of such use and indemnifies Vicor against all damages.
Vicor’s comprehensive line of power solutions includes high density AC-DC and DC-DC modules and
accessory components, fully configurable AC-DC and DC-DC power supplies, and complete custom power
systems.
Information furnished by Vicor is believed to be accurate and reliable. However, no responsibility is assumed by Vicor for
its use. Vicor components are not designed to be used in applications, such as life support systems, wherein a failure or
malfunction could result in injury or death. All sales are subject to Vicor’s Terms and Conditions of Sale, which are
available upon request.
Specifications are subject to change without notice.
Vicor Corporation
25 Frontage Road
Andover, MA 01810
USA
Picor Corporation
51 Industrial Drive
North Smithfield, RI 02896
USA
Customer Service: custserv@vicorpower.com
Technical Support: apps@vicorpower.com
Tel: 800-735-6200
Fax: 978-475-6715
