VICOR QPO-1

P R E L I M I N A RY
QuietPower ™
QPO-1-EVAL3
QPO-1 Evaluation Board, Micro Foot Print DC-DC Converters
Description
Features of the QPO-1
The QPO-1-EVAL3 is designed to allow full testing of
the QPO-1 and its various performance settings to
optimize final system design. The board offers switch
settings for the user to select preset values for the
Rhr, Rsc, and Rsa resistors. Solder pads are available
to mount user-selected values of these components if
required. Please refer to the QPO-1 product data
sheet, and the following pages for the proper
application of this board. The EVAL3 accommodates
Vicor’s quarter brick DC-DC converters with an input
up to 72 Vdc.
• >30 dB PARD attenuation, 1 kHz to 500 kHz
The QPO-1 output ripple attenuator SiP uses active
filtering to reduce output ripple and noise (PARD)
over 20 dB from 50 Hz to 500 kHz. The QPO-1
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
precise point-of-load regulation.
Other eval boards (see part numbering description)
allow easy evaluation with other DC-DC converters
or power supplies with standard terminations.
Typical Application
• >20 dB PARD attenuation, 50 Hz to 500 Hz 1
• 10A rating over a 3-30 Vdc operating range
• Supports precise point-of load regulation
• Up to 99% efficiency with power limit protection
• User selectable optimization of attenuation,
power dissipation & transient load response
• Peak detector function optimizes for ripple
amplitude variation automatically
• 1.0 x 1.0 x 0.2” SiP with BGA or LGA mounting
• Improves transient response of most DC-DC
converters and power supplies
• Reduces required number of output capacitors
to support dynamic loads.
• Patents Pending
Note 1: For off-line supplies 20dB attenuation can be achieved
down to 50Hz with additional capacitance added from the
VREF pin to the REFGND pin.
QPO-1 Performance
LOAD+
VOUT+
QPO OUT
QPO IN
QPO-1
SC
QPO IN (AC)
Rsc
SENSE+
SC
Cout
SC SET
CESR
REFGND
GND
VREF
SENSE-
QPO OUT (AC)
Rhr
VOUTLOAD-
LOAD CURRENT (DC) 1A/DIV
Figure 1 – SC/Trim supports applications that don’t
require remote sense.
Picor Corporation • www.picorpower.com
Figure 2 – Typical performance with a 3.3 Volt converter.
QPO-1-EVAL3 Data Sheet Rev. 1.1 Page 1 of 4
P R E L I M I N A RY
PICOR QPO-1
Optional Transient
Capacitors
3V to 30V Input Voltage
C6
External Load
10A Maximum
C7
Micro Application Board rev.2
LOADLOAD+
-
QPO IN
QPO OUT
7
1
+
+
GND
QPO-1
R11
SC
C9
2
C5
6
ENGINEERING SAMPLE
3
5
R5
R9
Slope Adjust
Bypass
1
O
N
VREF
UP
DOWN
SW2: SC Function
1: SC Capacitor
IN
OUT
2: SC Control Enabled Disabled
EARTH/Baseplate
SW1
R7
SW3
C10
-
R4
R6
R10
+
R3
4
COUT
XXXXA
R8
Input Supply
PHIL
QPO-1
SW2
O
N
Supply+
SupplyEarth
R1
US AND FOREIGN PATENTS, PATENTS PENDING
1 2
2
3
C8
12V
5V
3.3V
28V = All Off
Figure 3 - EVAL3 Board layout and measurement locations.
QPO IN
QPO OUT
QPO IN
QPO OUT
QPO IN
17
QPO IN
REFGND
VREF
SLOPE ADJ
GND
CESR
6
SC SET
COUT
5
15uF
CESR
GND
2
1
External Load
QPO-1
RAM SIP REV1H
R6
optional
C4
4.7nF
C6
270uF
C7
270uF
SW3
CAS-120B1
R7
user defined
2
BasePlate
QPO OUT
18
C9
TBD
C10
3.3uF
SC SET
SC
10
9
8
7
1
MH4
MH5
MH6
4.7nF
19
PEAK IN
3
Supply+
16
QPO OUT
QPO OUT
QPO OUT
QPO OUT
4
204-2ST
SC
C3
2
204-2ST
SW2A
1
R1
user defined
3
4
SW2B
GND
6
3
7
1
2
MICRO1
MICRO FOOTPRINT
20
3
15
C5
100uF
2
SC
1
QPO IN
QPO IN
QPO IN
QPO IN
GND
5
11
12
13
14
1
MH3
R11
TBD
4.7nF
4
2
MH1
4.7nF
Input Supply
3
QPO OUT
C2
BasePlate
C1
MH2
Supply-
VREF
QPO OUT
C8
optional
VREF
7
R5
2.67K
6
5
SW1C
204-213ST
4
3
2
R10
23.7K
8
9
11
12
R4
4.02K
SW1B
204-213ST
SW1A
204-213ST
1
R9
35.7K
10
R3
9.76K
R8
86.6K
SC SET
VREF
12V
5V
3.3V
Figure 4 - Schematic of EVAL3
Picor Corporation • www.picorpower.com
QPO-1-EVAL3 Data Sheet Rev. 1.1 Page 2 of 4
P R E L I M I N A RY
Switch Tables
Instructions For Use
The QPO-EVAL3 board has been designed to
accommodate a wide range of output voltages from
a micro footprint DC-DC converter.
The terminal block in the lower left-hand corner of
the pc board (labeled "Input Supply") is used to
provide the input voltage to the DC-DC converter.
The output load should be connected to the
terminal block on the right, labeled "External Load"
and should not exceed 10 Amps.
Switch 1 (SW1 in the lower-right corner of the pc
board) is used to set the appropriate headroom
voltage and SC current for converters with 12V, 5V
or 3.3 Vdc outputs. Optimal headroom and SC
current settings are pre-defined and the appropriate
components are populated on the board.
The board EVAL3 will also accommodate user
defined output voltages. With all SW1 switches in
the "down" position (open circuit), the switch
settings allow access to the open pads for R1 and R7.
The user must calculate a value for headroom
voltage setting resistor (R7) and the SC current
setting resistor (R1) and populate the pads with the
selected components. Originally, this position was
designed to be used with a 28V converter, hence the
reference to "28V - ALL OFF" on the pc board.
With the first switch of SW1 in the "up" position,
and the rest in the "down" position, the headroom
voltage and SC current setting is adjusted to work
with a 12V converter. With the second switch of
SW1 in the "up" position, the rest "down", the
converter is set to work with a 5V converter. With
the third switch "up", the rest "down", the board is
set to work with a 3.3V converter. This switching
network will parallel the switched in resistors with
R7 and R1. If a predefined voltage is to be used, R7
and R1 should not be populated. At no time should
more than one switch be in the "up" position to get
accurate results.
SW2 is used to engage the SC control function and
to add an additional bypass capacitor to the SC pin
of the converter. With the first switch of SW2 in the
"up" position, a 3.3uF capacitor (C10) is added to the
SC pin of the converter. With the second switch of
SW2 in the "up" position, the SC control circuit of
the QPO is connected to the converter. When the
switches are in the "down" position, the capacitor
and SC connection are opened and out of the circuit.
SW3 is used to engage the optional Slope Adjust
resistor when in the "up" position.
The QPO application board has Johnson Jacks
mounted on three key measurement points. These
jacks greatly reduce the amount of radiated noise
that gets picked up by the ground clip leads of the
scope probes. QPO IN is the input to the QPO from
the DC-DC converter. QPO OUT is the output of the
QPO where effects of the various settings can be
analyzed. VREF is the reference voltage that the QPO
uses to maintain a desired output voltage.
A resistor from this pin to ground will determine
the QPO’s operating headroom voltage (the voltage
drop between QPO IN and QPO OUT) according to
the following equation:
Rhr =
QPOout
* 2.5kΩ
Vhr
where;
Rhr is headroom resistor value,
QPOout is the voltage seen on the QPO’s output,
Vhr is the target headroom voltage.
The Rsc resistor is tied between QPOOUT and SC SET
pin and sets the correction current used to trim up
the converter to maintain a constant output voltage
on the QPO’s output. The value for the SC SET
resistor is calculated by the following equation:
Rsc =
Rin * Vout
Vrpt
where;
Rsc is SC SET resistor value,
Rin is the input resistance of the SC or TRIM,
Vout is the source output voltage,
Vrpt is the pre-trimmed reference of the
SC or TRIM.
On the application board there are two spots for
additional capacitors (C6 and C7) to be added to the
QPO’s input. These might be required if higher
transient steps are needed from higher output
voltage converters. These converters typically have
lower output capacitance than lower output voltage
converters do.
Picor Corporation • www.picorpower.com
QPO-1-EVAL3 Data Sheet Rev. 1.1 Page 3 of 4
R11 and C9 are used for filtering the input to the
QPO’s peak detector input. The QPO’s peak detector
circuit will increase the headroom of the QPO by
roughly half of the peak-to-peak ripple on the QPO’s
input. At low input voltage, the added headroom
might cause the SC circuit to trim up a converter to a
point where it shuts down due to an over-voltage
fault.
Ordering Information
Part Number
QPO-1-EVAL3
Description
Evaluation board for QPO-1
for Micro footprint DC-DC
Converters
There is a spot for adding an addition capacitor to
VREF (C8) if greater attenuation is needed at lower
frequencies.
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: [email protected]
Technical Support: [email protected]
Picor Corporation • www.picorpower.com • QPO-1-EVAL3 Data Sheet
P/N 27091
Rev. 1.1
9/03/10M