QPO-1 EVAL1 r2D Build Guide

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QPO-1-EVAL1
QPO-1-EVAL1 User’s Guide
Description:
Features:
The QPO-1-EVAL1 is designed to allow full testing of the QPO1LZ, along with its various performance options, to fully
optimize a final system design. The board offers two terminal
options for vertical or horizontal mounting. The user must
select the required values for the RHR, RSCSET and RSA resistors
and solder them in the designated positions before applying
power to the EVAL1. Please refer to the QPO-1LZ product
data sheet, schematics and the following pages for the proper
application of this board.
The QPO-1 output ripple attenuator SiP uses active filtering to
reduce output ripple and noise (PARD) over 30 dB from 500
Hz to 500 kHz and can be extended down to 50 Hz with
additional capacitance added to the VREF pin. The QPO-1LZ
operates over a voltage range from 3 to 30 VDC and supports
load currents as high as 10A. Output regulation is maintained
with remote sense or trim adjustment of the power supply.
The closed loop architecture improves transient response and
ensures quiet point-of-load regulation when used in
conjunction with the power supply’s control loop or trim
node.
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> 30 dB PARD attenuation, 1 kHz to 500 kHz
3 - 30 VDC operating range
10A rating
Supports precise point-of load regulation through
use of remote sensing or converter trimming.
Optional Start-up circuit included.
User selectable performance optimization for
attenuation, power dissipation, and transient
response
Horizontal or vertical mounting options.
Evaluation board includes a Johnson Jack for lownoise measurement of the QPO’s filtering
performance.
Figure 1 – Top View of Evaluation Board.
QPO-1 Performance:
The waveforms in Figure 2 high-light the QPO-1’s ability to
both filter a converter’s output ripple and maintain a
constant output voltage during a load transient. The input
voltage of the QPO-1 (dark blue) shows varying amplitude
and frequency PARD before and during the load transient, but
the QPO-1 output voltage (light blue) remains relatively
unaffected. The load transient is a 1A to 10A load step
(green).
The converter used is a Vicor Mini, 48V to 5V converter
(Model number: V48B5C200BN)
Figure 2 - PARD and Transient Attenuation
PICOR Corp.
Page 1 of 8
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QPO-1-EVAL1 User Guide, Rev 1.4
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QPO-1-EVAL1
QPO-1-EVAL1 SCHEMATIC:
J11
J12
J8
C1
15uF
RSENSE
51.1
J7
J3
QPO IN
J6
RP
1.00K
RSA
TBD
QPO OUT
Peak Det
CESR
SC
J5
SC Set
J9
RHR
CHR
CP
TBD
Opt
Opt
J6
Start-up Circuit
RSCSET
R2
TBD
DZ1
18V
C
VREF
J4
15uF
100
Slope Adj
J1
J2
CESR
VREF Gnd
RSU
Q1
IRLML5103TRPBF
20.0K
Gnd
CSU
1uF
J10
J1
Figure 3 – Evaluation board schematic.
QPO-1-EVAL1 BOM:
Qty
Description
Value
Designator
Vendor
Vendor Part Number
2
Capacitor,X7R
Ceramic,15uF,25V,1812
15uF
C1, CESR
TDK
C4532X7R1E156MT
1
Capacitor,X7R
Ceramic,1uF,50V,1206
1uF
CSU
TDK
C3216X7R1H105K
1
8
2
Diode,Zener,12V,0.15W,SOT-23
Samtec,0.2", Rt Angle Header
Connector,Johnson Jack
18V
Johnson Jack
DZ1
J1, J2, J3, J4, J5, J6, J7, J8
J11, J12
ON Semi
Samtec
Tektronix
BZX84C18LT1G
FWS-08-02-T-S-RA
131503100
1
Transistor,PFET,30V,0.6A
IRLML5103TRPBF
Q1
International
Rectifier
IRLML5103TRPBF
1
1
1
1
1
QPO-1LZ
Resistor,5%,0.25W,1206
Resistor,1%,0.25W,1206
Resistor,1%,0.25W,1206
Resistor,1%,0.25W,1206
QPO-1LZ
100
1.00K
51.1
20K
QPO-1
R2
RP
RSENSE
RSU
PICOR
Rohm
Rohm
Rohm
Rohm
QPO-1LZ
MCR18EZPJ101
MCR18EZHF1001
MCR18EZPF51R1
MCR18EZHF2002
INSTALLED COMPONENTS:
USER DEFINED COMPONENTS:
The QPO-1-EVAL1 board comes with the following
components pre-stuffed:
Remote Sense Components
C1, RSENSE
Start-up Assist Circuit
CSU, RSU, DZ1, R2, Q1
Peak Detector
RP
CESR
CESR
The QPO-1-EVAL1 board comes with the following
components not installed; values to be determined by
customer:
Headroom Resistor
RHR (not optional, must be
installed for proper
operation)
Headroom Capacitor
CHR (optional)
Slope Adjust
RSA (optional)
SC Function
CSC, RSCSET (optional)
Peak Detector
CP (optional)
PICOR Corp.
Page 2 of 8
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QPO-1-EVAL1 User Guide, Rev 1.4
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QPO-1-EVAL1
FUNCTION DESCRIPTIONS:
Slope Adjust:
The slope adjust function allows the user to modify the
voltage drop across the QPO-1 (headroom voltage)
dependent on the current passing through the QPO-1. This
function is used to maintain a constant power across the
QPO-1 over a varying range of load currents. The RSA resistor
can be calculated by using the following equation:
RSA 
0.05V I OUT
*
* 2.5k
A
VHR
Where; IOUT = Maximum change in load current (A)
VHR = headroom voltage change over load range (V)
RSA = slope adjust resistor (Ω)
The slope adjust feature can be disabled by either using a
large resistor value (100k or greater) for RSA or by omitting
this resistor entirely.
Headroom Adjust:
The RHR resistor is used to program the desired voltage drop
across the QPO-1. This voltage must be greater than the
ripple voltage that the QPO-1 is to filter, with additional
voltage added for the voltage drops in the attenuation path.
Like the RP resistor, the RHR resistor must always be installed
for proper operation. The value of RHR can be calculated
using this equation:
RHR 
QPOOUT * 2.5k
VHR
SC Function:
The function of the SC circuit is to use a converter’s trim or SC
(secondary control) pin to compensate for the voltage drop
across the QPO-1, thereby maintaining the desired output
voltage on the QPO’s output.
The RSCSET resistor (listed as RSC in the datasheet) determines
the amount of current the SC pin of the QPO-1 will source.
The current is calculated by dividing the headroom voltage
(the voltage drop from QPO_IN to QPO_OUT) by RSCSET.
RSCSET 
RIN * VOUT
VRPT
Where; VOUT = Nominal converter output voltage (V)
VRPT = internal reference voltage (V)
RIN = internal series resistor. (Ω)
When using one of Vicor’s Micro, Mini or Maxi converters,
the RIN = 1kΩ and the VRPT = 1.23V.
Figure 4 shows the QPO-1-EVAL1 board connected so as to
use the SC function to compensate for the QPO-1’s voltage
drop.
Remote Sense:
Compensation for the QPO-1’s voltage drop can be done
using the converter’s remote sense pins, if available. The onboard sensing network can be attached as is shown in Figure
5.
Where; RHR = headroom setting resistor value (Ω)
QPOOUT = the voltage on the QPO’s output (V)
VHR = the target headroom voltage (V)
If this resistor is omitted, then the reference pin will be at the
same voltage as the input pin, forcing the output pin to be
the same voltage as the input pin.
PICOR Corp.
Page 3 of 8
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QPO-1-EVAL1 User Guide, Rev 1.4
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QPO-1-EVAL1
Figure 4 – Evaluation board in SC configuration.
Figure 5 – Evaluation board in Remote Sense configuration.
PICOR Corp.
Page 4 of 8
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QPO-1-EVAL1 User Guide, Rev 1.4
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QPO-1-EVAL1
Figure 6 - Start-up waveforms; without (left) and with (right) the optional Startup circuit.
Start-up Circuit:
The start-up circuit (Figure 3) on the evaluation board is used
to connect the QPO-1’s reference pin to its input pin during
start-up. In both waveform pictures of Figure 6, the Output
Voltage (light blue) follows the VREF voltage (purple) of the
QPO-1.
In the picture to the left in Figure 6, without the optional
start-up circuit, the QPO-1 input voltage (the converter’s
output voltage) can be seen to be greater than the nominal
5V output of the converter. This is due to the QPO-1’s SC
circuit having greater headroom voltage during start-up and
therefore over-driving the SC of the converter. After about
40ms, the VREF voltage reaches its 5V pre-set limit and the
converter’s output voltage starts to drop, eventually
steadying out at 5.35V, the nominal output voltage plus the
QPO-1’s headroom voltage.
The potential problem with this start-up is that the converter
could fault due to its output being forced to be greater than
110% of the nominal value. For converters with lower
nominal output voltages, this could be very serious condition.
PICOR Corp.
Page 5 of 8
The waveforms to the right are the same converter with the
optional start-up circuit enabled. Here, the VREF is forced to
follow VIN, so VOUT follows as well. After about 25ms, the
start-up circuit releases the VREF pin and it adjusts it value
down to generate the proper headroom voltage across the
QPO-1. Using this method, there is no possibility of overdriving the converter and causing a fault.
Peak Detector:
The QPO-1 peak detector is used to adapt the headroom
voltage in response to increasing converter ripple. The
greater the ripple on the QPO-1’s input, the greater the
headroom voltage across the QPO-1. This feature can be
disabled by adding the CP capacitor to the evaluation board.
The addition of this capacitor creates an RC filter network
that filters out the converter’s ripple to the peak detector.
The RP resistor must always be installed for proper
operation. The peak detector creates the internal reference
voltage rail that gets divided down by the headroom resistor
RHR.
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QPO-1-EVAL1 User Guide, Rev 1.4
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QPO-1-EVAL1
www.picorpower.com
QPO-1-EVAL1 User Guide, Rev 1.4
Mounting Options:
PICOR Corp.
Page 6 of 8
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QPO-1-EVAL1
Mechanical Drawing:
Ordering Information
Part Number
QPO-1-EVAL1
PICOR Corp.
Page 7 of 8
Description
Evaluation Board for QPO-1L
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QPO-1-EVAL1 User Guide, Rev 1.4
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QPO-1-EVAL1
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: [email protected]
Technical Support: [email protected]
Tel: 800-735-6200
Fax: 978-475-6715
PICOR Corp.
Page 8 of 8
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QPO-1-EVAL1 User Guide, Rev 1.4