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7 A VI Chip®EMI Filter SiP
Quiet-Power®
QPI-12
Product Description
The QPI-12 EMI filter is specifically designed to attenuate
conducted common-mode (CM) and differential-mode (DM)
noise of Vicor’s VI 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
7 A loads up to 85°C (TA) without de-rating.
Designed for the telecom bus range, the VI Chip EMI filter
supports the PICMG® 3.0 specification for filtering system
boards to the EN55022 Class B limits.
Features
•45 dB CM attenuation at 1 MHz (50 Ω)
•75 dB DM attenuation at 1 MHz (50 Ω)
•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 4.2 mm, open-frame
•Low profile LGA package
•-40° to +125°C PCB temperature (see Figure 6)
•Efficiency >99%
•TÜV Certified
Applications
•VI Chip input EMI filter
•Telecom and ATCA boards
Shield
BUS+ QPI+
BUS- QPI-
IN+
IN-
OUT+
OUT-
IN+
IN-
OUT+
OUT-
Shield Plane
BUS+
BUS-
Cha ssis/Shield
CB1
CIN
LOAD
CY1 CY2 CY3 CY4
Optional Chassis
Connection
L
PRM VTM
++
Typical Applications
[a] CB1 capacitor, referenced in all schematics, is a 47 uF electrolytic; United Chemi-Con EMVE101ARA470MKE0S or equivalent.
CY1 to CY4, referenced in all schematics, are 4.7 nF hi-voltage safety capacitors; Vishay VY1472M63Y5UQ63V0 or equivalent.
Figure 2 — Typical QPI-12 application schematic with Vicor’s PRM and VTM modules. [a]
Figure 1 — QPI-12LZ (~1/2 in2area)
Shield
BUS+ QPI+
BUS- QPI-
IN+
IN-
OUT+
OUT-
Shield Plane
BUS+
BUS-
Cha ssis/Shield
CB1
CIN
LOAD
CY1 CY2 CY3 CY4
Optional Chassis
Connection
BCM
++
Figure 3 — Typical QPI-12 application schematic with Vicor’s BCM module. [a]
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QPI-12
Order Information
Part Number Description
QPI-12LZ[b] QPI-12 LGA package, RoHS compliant
QPI-12LZ-01 QPI-12 LGA package, RoHS compliant, open-frame package
Evaluation Board Also Available
QPI-12-CB1 A QPI-12LZ mounted on a carrier board that can hold either a stand-alone BCM or a paired PRM/VTM eval board available from Vicor.
Name Rating
Input voltage, BUS+ to BUS-, continuous -80 to 80 Vdc
Input voltage, BUS+ to BUS-, 100 ms transient -100 to 100 Vdc
BUS+/ BUS- to Shield pads, hipot -1500 to 1500 Vdc
Input to output current, continuous @ 25°C (TA) 7 Adc
Power dissipation, @ 85°C (TA), 7 A [c] 1.85 W
Operating temperature - TA-40 to 125 °C
Thermal resistance[c] - RθJ-A, using PCB layout in Figure 25 30°C/W
Thermal resistance[c] - RθJ-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.
Absolute Maximum Ratings
Exceeding these parameters may result in permanent damage to the product.
Parameter Conditions Min Typ Max Unit
BUS+ to BUS-, input range Measured at 7 A, 85°C ambient temperature [c] 80 Vdc
BUS+ to QPI+, voltage drop Measured at 7 A, 85°C ambient temperature [c] 130 mVdc
BUS- to QPI-, voltage drop Measured at 7 A, 85°C ambient temperature [c] 130 mVdc
Common-mode attenuation VBUS = 48 V, frequency = 1.0 MHz, line impedance = 50 Ω45 dB
Differential-mode attenuation VBUS = 48 V, frequency = 1.0 MHz, line impedance = 50 Ω75 dB
Input bias current at 50 V Input current from BUS+ to BUS- 10 uA
[b] QPI-11LZ is a non-hermetically sealed package. Please read the “Post Solder Cleaning” section on Page 11.
[c] See Figure 6 for the current de-rating curve.
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QPI-12
Pin Name Name Description
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
Pad Descriptions
BUS+
BUS+
BUS–
BUS– QPI–
QPI–
QPI+
QPI+
Shield Shield
34
5
6
7
8
9
2
1
10
LGA Pattern (Top View)
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QPI-12
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-12CB1 carrier is designed to
accept both the PRM/VTM combination of evaluation boards, as well as
the stand-alone BCM evaluation board.
The 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 VI 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 VI Chip evaluation boards.
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QPI-12
Figure 5 — Baseplate EMI test setup using the QPI-12-CB1 carrier board with VI 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 tries to propagate to the input
source.
There are two basic topologies for the connection of the recirculating “Y”
capacitors. In Figure 4 the open-frame topology is shown in Picor’s EMI
test setup. The “Y” capacitors (CY1 to CY4) recirculate the EMI signals
between the positive input and output, and the negative input and
output of the power conversion stage.
Figure 5 shows the baseplate topology of recirculating “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.
Figure 6 — Current de-rating over ambient temperature range.
Current De-Rating — Mounted to QPI-12-CB1 Evaluation Board
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QPI-12
Figure 7 — Attenuation curves into a 50 Ω line impedance, bias from a 48 V bus.
QPI Insertion Loss Measurements
BUS IN
SIG
Chassis
LISN
BUS IN
SIG
Chassis
LISN
Shield
BUS+ QPI+
BUS- QPI-
INA
INB
SIG
50
CSIG
LO A D
IPRO BE
IPRO BE
47uF
VBUS
Ω
Figure 8 — Test set up to measure differential-mode EMI currents in Figure 7.
QPI Insertion Loss Test Circuits
Equation 1.— Insertion Loss = 20 *log *
[
IINA
]
IINB
BUS IN
SIG
Chassis
LISN
BUS IN
SIG
Chassis
LISN
Shield
BUS+ QPI+
BUS- QPI-
50
47uF
VBUS
Ω
CSIG
LO A D IPRO BE
IPRO BE
INA
INB
SIG
Figure 9 — Test set up to measure common-mode EMI currents in Figure 7.
Figure 10 — VTM V048F030T070-CB with 160 W load.
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QPI-12
Attenuation Plots — QPI-12 with PRM P048F048T24AL-CB and various VTM modules, connected in baseplate configuration, as shown in Figure 4.
Figure 12 — VTM V048F240T012-CB with 172 W output load.
Figure 11 — VTM V048F120T025-CB with 180 W load.
Figure 13 — VTM V048F480T006-CB with 153 W load.
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QPI-12
Figure 14 — BCM B048F030T21-EB with 160 W load.
Attenuation Plots — QPI-12 with various BCM modules, connected in open frame configuration, as shown in Figure 18.
Figure 16 — BCM B048F240T30-EB with 172 W load.
Figure 15 — BCM B048F120T30-EB with 180 W load.
Figure 17 — BCM B048F480T30-EB with 152 W 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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QPI-12
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 recirculating 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.
Shield
BUS+ QPI+
BUS- QPI-
IN+
IN-
OUT+
OUT-
BUS+
BUS-
Chassis/Shield
CB1 CIN LOAD
Optional Chassis
Connection
BCM
++
CY1
CY2
4.7nF
4.7nF
Figure 18 — BCM converter in open-frame configuration with the output connected to chassis/earth.
Converter Output Grounding — Recommended configurations
Figure 20 — Total noise plot of BCM with its output return connected to
chassis, as shown in Figure 18, 125 W load.
Shield
BUS+ QPI+
BUS- QPI-
IN+
IN-
OUT+
OUT-
IN+
IN-
OUT+
OUT-
BUS+
BUS-
Chassis/Shield
CB1 CIN LOAD
CY2
Optional Chassis
Connection
L
PRM VTM
++
CY1 C Y2
CY3
4.7nF4.7nF
47uF
4.7nF
Figure 19 — PRM/VTM in open-frame configuration with the output connected to the chassis/earth.
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QPI-12
Mechanical Package Drawings
0.508" [12.903 mm]
0.996" [25.298 mm] 0.196" [4.978 mm]
0.006" [0.15mm] max.0.006" [0.15mm] max.
QPI-12LZ
U.S. and Foreign Patents/Patents Pending
Lot # Date Code
Pin 1 indicator
Figure 21 — Lidded package dimensions, tolerance of ±0.004”
12LZ-01
0.979" [24.867 mm] 0.164" [4.166 mm]
0.330 [8.382 mm]
0.006" [0.15mm] max.0.006" [0.15mm] max.0.006" [0.15mm] max.
0.489" [12.421 mm]
Pin 1
Figure 22 — Open open-frame package dimensions, tolerance of ±0.004”. Pick and place from label center.
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 33
Peak Reflow Temperature °C/20 seconds 245 245 IPC/JEDEC J-STD-020D
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QPI-12
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 6 mil stencil thickness, 80% of LGA pad area coverage. LGA package dimensions are for both the open-frame and lidded
versions of the QPI-12.
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QPI-12
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 one 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 overlap 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 two-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 QuitePower 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
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 makes no
representations or warranties with respect to the accuracy or completeness of the contents of this publication. Vicor reserves the right to make
changes to any products, specifications, and product descriptions at any time without notice. Information published by Vicor has been checked and
is believed to be accurate at the time it was printed; however, Vicor assumes no responsibility for inaccuracies. Testing and other quality controls are
used to the extent Vicor deems necessary to support Vicor’s product warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
Specifications are subject to change without notice.
Vicor’s Standard Terms and Conditions
All sales are subject to Vicor’s Standard Terms and Conditions of Sale, which are available on Vicor’s website or upon request.
Product Warranty
In Vicor’s standard terms and conditions of sale, Vicor warrants that its products are free from non-conformity to its Standard Specifications (the
“Express Limited Warranty”). This warranty is extended only to the original Buyer for the period expiring two (2) years after the date of shipment
and is not transferable.
UNLESS OTHERWISE EXPRESSLY STATED IN A WRITTEN SALES AGREEMENT SIGNED BY A DULY AUTHORIZED VICOR SIGNATORY, VICOR DISCLAIMS
ALL REPRESENTATIONS, LIABILITIES, AND WARRANTIES OF ANY KIND (WHETHER ARISING BY IMPLICATION OR BY OPERATION OF LAW) WITH
RESPECT TO THE PRODUCTS, INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OR REPRESENTATIONS AS TO MERCHANTABILITY, FITNESS FOR
PARTICULAR PURPOSE, INFRINGEMENT OF ANY PATENT, COPYRIGHT, OR OTHER INTELLECTUAL PROPERTY RIGHT, OR ANY OTHER MATTER.
This warranty does not extend to products subjected to misuse, accident, or improper application, maintenance, or storage. Vicor shall not be liable
for collateral or consequential damage. Vicor disclaims any and all liability arising out of the application or use of any product or circuit and assumes
no liability for applications assistance or buyer product design. Buyers are responsible for their products and applications using Vicor products and
components. Prior to using or distributing any products that include Vicor components, buyers should provide adequate design, testing and
operating safeguards.
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.
Life Support Policy
VICOR’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS
PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL COUNSEL OF VICOR CORPORATION. As used herein, life support
devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and whose failure to perform
when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the
user. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or system or to affect its safety or effectiveness. Per Vicor Terms and Conditions of Sale, the user of Vicor products
and components in life support applications assumes all risks of such use and indemnifies Vicor against all liability and damages.
Intellectual Property Notice
Vicor and its subsidiaries own Intellectual Property (including issued U.S. and Foreign Patents and pending patent applications) relating to the
products described in this data sheet. No license, whether express, implied, or arising by estoppel or otherwise, to any intellectual property rights is
granted by this document. Interested parties should contact Vicor's Intellectual Property Department.
Vicor Corporation
25 Frontage Road
Andover, MA 01810 USA
Picor Corporation
51 Industrial Drive
North Smithfield, RI 02896 USA
email
Customer Service: custserv@vicorpower.com
Technical Support: apps@vicorpower.com
The products described on this data sheet are protected by the following U.S. Patents Number:
6,898,092
