Picor Corporation www.picorpower.com
QPI-8L Data Sheet Rev. 1.0 Page 1 of 8
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Features
>40 dB CM attenuation at 250 kHz
>70 dB DM attenuation at 250 kHz
80 Vdc (max input)
100 Vdc surge 100 ms
1,500 Vdc Hi-pot hold off to Shield Plane
-48 V and -60 V Telecom/ATCA BUS capability
Provides safe powered backplane board insertion
6 A Breaker with delay plus 12 A limiter
1.0" x 1.0" x 0.2" SiP (System-in-a-Package)
QPI-8L Land Grid Array (LGA)
-40 to +100C PCB temperature (see Figure 5)
Hot-Swap and filter combination saves space
Efficiency >99%
Connects between OR'ing diodes and power
converter input hold-up capacitors
Patents pending
Application
ATCA PICMG
3.0 boards
Block Diagram
Typical Attenuation
QPI+
SW
BUS+
EMI Filter
QPI-
SH
IELD
Hot Swap Function
PowerGood
SHIELD
OV
SW
UVEN
BUS-
BUS+
PWRGD
QPI+
QPI-
QPI-8
Figure 1 - Block diagram, EMI filter and Hot-Swap
Figure 2 - QPI-8 network analyzer attenuation curves
Description
The QPI-8 is the industry's first System-in-a-Package (SiP)
designed to integrate a total Hot-Swap function with an
active EMI filter. The product aligns with the
AdvancedTCA
TM
PICMG
3.0, requirements for hot
insertion and board level conducted noise limitations. The
EMI filter provides active conducted common-mode (CM)
and differential-mode (DM) noise attenuation from
150 kHz to 30 MHz. The QPI-8 is designed for use on a 48
or 60 Volt DC bus (36 76 Vdc). The in-rush current limit
and circuit breaker are designed to satisfy the 200 W per
board PICMG
3.0 limit up to 70C PCB temperature
around the QPI-8.
The undervoltage and overvoltage thresholds can be
trimmed separately via the UVEN and OV inputs using
external series resistors. The Powergood active-high
output provides opto-coupler drive for a converter's
active-low enable (see Figure 9a) or active-high by
connecting the diode in series with the Powergood
output (see Figure 9b).
The QPI-8 is available in a 1.0" x 1.0" x 0.2" SiP (System-in-
a-Package) with LGA mounting. QPI-EVAL1 kits are
available with a mounted QPI-8 and screw terminals for
easy insertion and testing. For more information on
Evaluation Boards visit us online at picorpower.com.
QPI-8L
QuietPower
TM
AdvancedTCA
TM
Hot-Swap SiP With Active EMI Filter
Picor Corporation www.picorpower.com
QPI-8L Data Sheet Rev. 1.0 Page 2 of 8
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Absolute Maximum Ratings
Exceeding these parameters may result in permanent damage to the product.
Electrical Characteristics
Parameter limits apply over the operating temp. range unless otherwise noted.
Pins
Parameter
Notes
Min
Typ
Max
Units
BUS+, SW, PWRGD to BUS- Input voltage
Continuous
-0.5
80
Vdc
BUS+, SW, PWRGD to BUS- Input voltage
100 ms transient
100
Vdc
BUS+/BUS- to Shield
BUS inputs to shield hi-pot
+/-1500
Vdc
QPI+ to QPI-
Load current
Pulsed limit @ 25C
12
Adc
Package
Power dissipation
@ 25C
4.0
W
Package
Operating temperature
PCB to QPI Interface
-40
100
C
Package
Thermal resistance ja
Free Air
50
C/W
Package
Junction temperature
Tb = 100C; Pd = 4 W @15 C/W
160
C
Package
Thermal resistance
PCB layout dependent
(Note 1)
15
C/W
Package
Storage temperature
-40
125
C
Package
Re-flow temperature
20 s exposure
212
C
All pins
ESD
HBM
+/-2
kV
Symbol
Parameter
Notes
Min
Typ
Max
Units
V
b+b-
BUS+ to BUS- input range
Measured at I
Load
= 5 A
(Note 2)
UV
80
Vdc
V
+oi
BUS+ to QPI+ voltage drop
Measured at I
Load
= 5 A @ 100C
(Note 2)
100
mVdc
V
-oi
BUS- to QPI- voltage drop
Measured at I
Load
= 5 A @ 100C
(Note 2)
250
mVdc
CMA
Common-mode attenuation
VBUS = 48 V; Frequency = 250 kHz
45
dB
DMA
Differential-mode attenuation
VBUS = 48 V; Frequency = 250 kHz
75
dB
I BUS+ to BUS-
Input bias current at 80 Volts
Input current from BUS+ to BUS-
15
mA
IPG QPI+ to QPI- Load current prior to PWRGD
Critical maximum DC load
25
mA
UV
Undervoltage threshold rising
Controller disabled to enabled
34
V
UVHYS
Undervoltage hysteresis falling
Controller enabled to disabled
UV 2 V
V
OV
Overvoltage threshold rising
Controller enabled to disabled
76
V
OVHYS
Overvoltage hysteresis falling
Controller disabled to enabled
OV 4 V
V
PWGSAT
Powergood low voltage
IPWG = 1 mA
0.2
0.6
V
PWGLK
Powergood high leakage
VPWG = 90 V
1
A
Note 1: Refer to Figure 15 and QPI application note QPI-AN1 for critical PCB layout guidelines to achieve this thermal resistance when
reflowed onto the PCB.
QPI 8
SIP Package
(Bottom View)
9 10 11 12
4 3 2 1
8
7
6
5
13
14
15
16
NC PWRGD
OV
BUS+
SHIELD SW
BUS-
QPI+
QPI-
BUS+
UVEN
SW
BUS-
Pin Descriptions
SiP Package Outline
(bottom view)
Pin
Name
Description
1, 16
BUS-
Negative bus potential
2, 3, 15
SW
Negative rail controlled by hot
insertion function.
4
SHIELD
Shield connects to the converter
shield and Y-capacitor common
point via RY. See Figures 9a and 9b.
5, 6
QPI-
Negative input to the converter
7, 8
QPI+
Positive input to the converter
10
PWRGD
Open collector output that asserts
low when power is NOT good.
12, 13
BUS+
Positive bus potential
14
UVEN
High side of UV resistor divider
11
OV
High side of OV resistor divider
9
Not used
No connection
Note 2: Refer to Figure 5 for current derating curve.
Picor Corporation www.picorpower.com
QPI-8L Data Sheet Rev. 1.0 Page 3 of 8
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Applications
EMI
The QPI-8 is an active EMI filter providing conducted
common-mode and differential-mode attenuation from
150 kHz to 30 MHz. Designed for the telecom and ITE bus
range, the QPI supports the PICMG
3.0 specification for
filtering system boards to the EN 55022 Class B limit.
The QPI-8 attenuates conducted noise and provides the
Hot-Swap function required in redundant systems,
minimizing design time compared to using discrete
approaches while minimizing the uncertainty that the
system will pass the compliance requirements.
The plots in Figures 3 and 4 were taken using the standard
50/50H LISN and measurement conditions with the
peak detection mode of the spectrum analyzer for a
conducted EMI test. The results show the total noise
spectrum for a particular converter and load compared to
the CISPR22 EN 55022 Class B Quasi-peak detection limit.
The plot in Figure 4 shows the effect of inserting a QPI-8
filter between the DC bus and the converter input under
the same operating conditions as in Figure 3. The resulting
plot shows the QPI-8 is effective in reducing the measured
prefiltered total noise spectrum to well below the
EN 55022 Quasi-peak detection limit. Using the Quasi-
peak detection measurement mode would result in lower
amplitudes by the error factor this method introduces.
Applications
Hot-Swap
The QPI-8 6 Amp rating provides filtering for up to
288 Watts of power from a 48 V bus with a 70C PCB
temperature. It is well suited for the 200 Watt per board
limit in the PICMG
3.0. The 1.0" x1.0" x 0.2" surface
mount LGA package provides ease of manufacturing by
eliminating through-hole assembly. The current derating
curve shown in Figure 5 should be used when the PCB
temperature that the QPI-8 is mounted to exceeds 70C.
The QPI-8 is designed to have an undervoltage range of
32 V to 34 V set points when the UVEN pin is tied directly
to the BUS+ pin. The QPI-8 becomes enabled when the
input voltage exceeds 34 V and continues to work down
to 32 V before being disabled.
The QPI-8 overvoltage range is designed to be 72 V to
76 V when the OV pin is tied directly to the BUS+ pin. The
QPI-8 remains functioning until the input voltage
surpasses 76 V, where the QPI-8 will shutdown until the
input voltage falls below 72 V.
External resistors can be added (see Figures 9a and 9b) to
trim the UV and OV trip points higher. The graph in
Figure 6 shows the trimming effect for a range of external
series resistors. The equations in Figure 7 can be used to
calculate the UV and OV thresholds.
Figure 3 Conducted EMI profile of a DC-DC converter.
Figure 4 Conducted EMI profile of a DC-DC converter with QPI-8.
0
10
20
30
40
50
60
70
80
90
100
PCB to QPI Interface Derating Curve Over Temperature (Deg. C)
QPI Differential Current (A)
8
6
4
2
0
Figure 5 QPI-8 current derating curve over temperature.
UVEN
LO
= 2.5 (RUVEN + 108450)
8450
UVEN
HI
= 2.5 V + (RUVEN + 100 K) (316 A)
OV
LO
= 2.5 V + (ROV + 200 K) (348 A)
OV
HI
=
2.5 (ROV + 206800)
6800
It is critical to keep the load current on the converter's
input capacitor to less than 25 mA during the initial
power-up phase. This limit is set by the current limit level
and the duty cycle of the circuit breaker timer.
Once Powergood has been asserted the full load can
be enabled.
An external capacitor CE, shown in Figures 9a and 9b, will
provide the required UVEN hold-up filtering during the
ATCA's 5 ms, zero-volt BUS transient requirement. Figure 8
shows the effects of CE during a BUS transient event.
Using a 2.2 F CE capacitor and 1 mF of converter input
capacitance will enable this circuit to support a 42 W load
for the 5 ms transient. The Powergood state of the QPI-8
remains unchanged during this transient, allowing the
converter to maintain its output power to the load.
To prevent the QPI-8 from going into a fault mode and
deasserting the Powergood signal after the transient, the
converter's input capacitors must be sized so that they can
be completely restored in the time of one 12 A current
pulse, about 1 ms, and still maintain the required input
current of the converter. If greater bulk capacitance is
required for higher loads, then the circuit in Figure 9c
could be used to slowly charge the capacitors. To reduce
bulk capacitance and take advantage of the V
2
energy
relationship, a boost circuit with a switch-over function
can be used to charge fewer bulk storage capacitors to a
higher voltage.
Picor Corporation www.picorpower.com
QPI-8L Data Sheet Rev. 1.0 Page 4 of 8
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Figure 8
5ms BUS transient, 42 W load
CH1: VBUS, CH3: PWRGD, CH4: Converter load current
0 5000
10000
15000
20000
25000
30000
Series Resistor
Voltage
90.00
80.00
70.00
60.00
50.00
40.00
30.00
OV-HI
OV-LO
UV-HI
UV-LO
Figure 6 Trimming UV/OV with external series resistor.
Figure 7 UVEN and OV resistor equations.
BUS+
RC
RB
CHOLD-UP
PWRGD
BUS
20 V
Picor Corporation www.picorpower.com
QPI-8L Data Sheet Rev. 1.0 Page 5 of 8
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Figure 9a Typical ATCA System with QPI-8 with active-low enable input
(Refer to Figure 15 and QPI-AN1 application note for critical PCB layout guidelines)
Figure 9b Typical ATCA System with QPI-8 with active-high enable input
(Refer to Figure 15 and QPI-AN1 application note for critical PCB layout guidelines)
BUS
SUPPLY
QPI-8
CONVERTER
ENABLE A
ENABLE B
BUS+
SW
BUS-
CB
47
F
CE
ROV
RUVEN
UVEN OV
PWRGD
75K
QPI+
QPI-
VIN+
ON/OFF
VIN-
CIN
CY
PCB plane under converter
VOUT+
VOUT-
CY
SHIELD
CY
RY
PE
CY
PWRGD
BUS-
Figure 9c Powergood controlled, auxiliary bulk storage capacitor charging circuit.
C
HOLD-UP
=
2* E
(V
PT2
V
UVLO2
)
where:
E = Hold-up energy
V
PT
= Pre-transient voltage
V
UVLO
= Converter's UV limit
BUS
SUPPLY
QPI-8
CONVERTER
ENABLE A
ENABLE B
BUS+
SW
BUS-
CB
47
F
CE
ROV
RUVEN
UVEN OV
PWRGD
75K
QPI+
QPI-
VIN+
ON/OFF
VIN-
CIN
CY
PCB plane under converter
VOUT+
VOUT-
CY
SHIELD
CY
RY
PE
BUS-
CY
PWRGD
50K
BUS-
Performance Waveforms
Start-up
The following oscilloscope pictures show the Hot-Swap
BUS- current, QPI- to Bus- voltage and PWRGD (Powergood)
to BUS- output voltage of the QPI-8 during operation.
Figures 10 and 11 are the QPI-8's in-rush characteristics
under two load capacitance conditions.
In Figure 10 a 470 F capacitor required roughly 170 ms to
completely charge from a 48 V bus voltage. The QPI-8 can
drive large amounts of bulk capacitance, as shown in
Figure 11 with a 4700 F load capacitance. Under this
condition the PWRGD signal takes about 8.7 seconds to go
high after the UVEN input is pulled high upon the
completed insertion of the board into the shelf. Figure 11's
time-scale is too long to show the current pulses that
charge the bulk capacitance.
After insertion, when the UVEN voltage exceeds 34 V the
UV detection fault is cleared, the QPI-8 goes through a
delay cycle (~15 ms) to allow for system de-bounce and
stabilization. After this time, the QPI- to BUS- path is
turned on and current is allowed to pass, monitored by
the current sense function. Initially the current level
exceeds the 6 A circuit breaker limit, the event timer starts
and the Powergood state is not valid. The sense function
and linear control loop will allow twice the circuit breaker
current to pass. If the current does not drop below the
circuit breaker level prior to reaching the timer limit,
typically 275 s, the QPI- to BUS- path will open. The
effective duty cycle under the current limit condition is
approximately 1%. Once the load capacitors are fully
charged to the input bus potential, the load condition
falls below 6 A and the PWRGD pin is asserted high,
providing that the bus supply is still within the UV and
OV range.
Transient Protection and Recovery
Figures 12 and 13 show the QPI-8's ability to handle low
resistance shorts (<2 ) at the load terminals to emulate
fast and slow blown fuse events. In Figure 12, the
transient short is 2 seconds long and the QPI- to BUS- path
is opened within 400 s of this occurrence.
Figure 13 demonstrates the QPI-8's performance with a
short circuit on its output. The QPI-8 remains in a low duty
cycle mode until the short is removed, then restarts normally.
Picor Corporation www.picorpower.com
QPI-8L Data Sheet Rev. 1.0 Page 6 of 8
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Figure 10 470 F capacitor @ 48 V
CH1: PWRGD, CH2: QPI- to BUS-, CH4: BUS- current
Figure 11 4700 F capacitor @ 72 V
CH1: PWRGD, CH2: QPI- to BUS-, CH4: BUS- current
Figure 12 2 second short circuit
CH1: PWRGD, CH2: QPI- to BUS-, CH4: BUS- current
Picor Corporation www.picorpower.com
QPI-8L Data Sheet Rev. 1.0 Page 7 of 8
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QPI-8 PCB Layout Considerations
For optimal QPI-8 filtering performance, care must be
taken when routing the signal paths of RY (see Figures 9a
and 9b) and the shield connections on the PC board. The
RY resistor must connect between the converter's shield
plane and the shield pin of the QPI-8. The connection to
the chassis or protective earth, if required, should be
taken directly from the QPI-8 shield pin as shown in
Figures 9a and 9b.
Figure 15 shows how this can be accomplished by using
the QPI-8's shield pin to bridge the connection between
RY and PE without allowing any parasitic paths that might
circumvent the QPI-8 and degrade filtering performance.
Reference can be made to the QPI-AN1 application note
for critical PCB layout recommendations regarding filter
performance, but use the QPI-8 pin/pad locations. Some
systems may require the converter's positive or negative
input or output 'terminal' to be connected to PE
(Protective Earth) ground for safety or other
considerations.
When using the QPI in this situation this 'terminal' must
be connected to the converter shield plane created in the
PCB layout under the converter. Because the PE path may
pass excessive current under a fault condition the
resistance of this path may be limited to a low resistance
value. To meet the resistance requirement without
degrading filter performance RY can be replaced by a
4.7 H inductor rated for the fault current condition
maintaining low power dissipation during a fault until the
protection device clears. The shield return PCB traces must
be sized to handle this current as well.
0.000
0.100
0.300
0.492 0.441
0.441
0.100
0.300
0.492
0.000
0.100
0.300
0.492
0.400
0.441
0.441
0.400
0.100
0.300
0.492
QPI-8 SIP Package
(Bottom View)
0.9843
0.8000
0.9843
0.0200
0.1773
14 places
45.000
0.1250
0.0820
0.0625
0.0820
0.0820
R0.0410
Figure 13 Start-up into short circuit
CH1: PWRGD, CH2: QPI- to BUS-, CH4: BUS- current
Figure 14 LGA Pad, package height and pad location
dimensions in inches.
BUS-
BUS+
QPI+
SHIELD
QPI-
0.4410
0.4410
UVEN
SW
OV NC
PWRGD
SHIELD
PLANE
UNDER
CONVERTER
RY
Figure 15 Recommended PCB layout pattern.
0.1310
0.0880
0.0655
0.0440
0.0440
0.0880
2 places
14 places
0.000
0.100
0.300
0.100
0.300
0.397
0.397
0.441
0.441
0.485
0.485
0.000
0.100
0.300
0.441
0.397
0.485
0.000
0.100
0.300
0.397
0.485
QPI Package Outline
QPI PCB Pad Pattern
(Top View)
R0.0440
0.492
Figure 16 Recommended PCB receiving footprint.
Part Number
Description
QPI-8L
QPI-8, Land Grid Array Package
Ordering Information
Picor Corporation www.picorpower.com QPI-8L Data Sheet
P/N 30329 Rev. 1.0 6/05
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Vicor's comprehensive line of power solutions includes high-density AC-DC & DC-DC modules
and accessory components, fully configurable AC-DC & 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. No license is granted by implication or otherwise under any patent or patent
rights of Vicor. 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, USA 01810
Tel: 800-735-6200 Fax: 978-475-6715
Email
Vicor Express: vicorexp@vicr.com
Technical Support: apps@vicr.com
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