QPO-2-EVAL1 Data Sheet

®
QP0-2-EVAL1
QUIETPOWER ™
Evaluation Board for QPO-2 Active Output Filter
converter. The RSL resistor shown in Figure 4 of the
product datasheet (not on the evaluation board) can be
used to limit the correction current sourced from the
Adjust+ circuit if needed during start-up preventing the
converter from tripping OVP.
The QPO-2-EVAL1 board provides an easy to use
evaluation platform for testing the QPO-2 in a lowvoltage system. A filtered voltage range of 0.3 Vdc to 5.5
Vdc at output load currents up to 20A can be
accomplished. A low current bias supply is required at the
VAUX input in the range of 7 to 12 volts respectively to
the output voltage range. The board comes with a QPO-2LZ
and some essential external components pre-mounted.
Please refer to the QPO- 2 datasheet for product details.
Terminals for horizontal or vertical mounting are also
provided. The user must mount and select component
values for RHR, RSC, RSL and RSA based on their system needs.
RHR is the headroom voltage setting resistor that will
determine the voltage dropped across the QPO-2. The RSA
resistor is for the slope-adjust option, which can be used
to reduce the amount of voltage across the QPO-2
depending on load current. This reduced drop in voltage
will result in a lower power loss across the QPO-2
providing greater efficiency but lower attenuation. An
optional capacitor, CHR, can be added to extend the lowfrequency attenuation range of the QPO-2.
RCP will preset the QPO-2’s reference voltage to a value
close to the desired steady-state value. This reduces the
time required for the QPO-2’s output to reach the
steadystate output voltage. There is a provision for a startup circuit (Q1 RDLY D1 CDLY) if the initial headroom
voltage needs to start from zero and increase gradually to
the set headroom voltage. Remote sense components (CRS
RRS), Figure 3 of the product datasheet, are mounted on
the evaluation board.
The RP resistor connects the QPO-2’s peak detection circuit
to the input voltage rail. The peak detector will adapt the
headroom voltage by adding half the peak-to-peak ripple
voltage to the headroom. Internally, the QPO-2 has a
0.1uF capacitor on its peak detector pin that allows the
user to filter out the converter’s ripple with an
appropriate RP resistor value, disabling the peak detector.
This filtering is enabled by using a low resistance value for
RP, such as a zero ohm that comes pre-installed on the
QPO-2 Eval board.
When remote sensing is not used RSC is the current
programming resistor that determines the current sourced
by the QPO-2’s Adjust+ pin to drive the TRIM pin of a
J1
VAUX
QPO_IN
QPO_OUT
RCP
RP
0
CRS
15 µF
D1
J8
SENSE+
J5
ADJUST/SC
MA111
RRS
51.1
QPO_OUT
CDLY
0.1 µF
Q1
IRLML6401
15 PEAK IN
ADJUST
16 ADJUST+/19 GND
20 GND
J4
GND
VREF
PEAKIN
VAUX
QPO OUT
QPO OUT
QPO OUT
QPO OUT
SC SET
1
17
8
7
6
5
QPO_OUT
J2
QPO–OUT
J3
QPO–OUT
SCSET
RSC
2
3
REFGND
RDLY
20 K
SLOPE ADJ
QPO_IN
QPO IN
QPO IN
QPO IN
QPO IN
QPO IN
VREF/RUP
11
12
13
14
18
RCP/RDN
10 9
Low Voltage Start-up Circuit
GND
J7
QPO–IN
VAUX
J6
QPO–IN
4
J9
GND
J10
GND
RSA
RHR
CHR
VREF
Figure 1 - Evaluation board schematic
Picor Corporation • www.picorpower.com
QPO-2-EVAL1 Data Sheet Rev. 1.2 Page 1 of 2
Figure 2 - Figure 2 – Evaluation Board Layout
* Note: Components Q1, D1, RDLY and CDLY are for an optional start-up circuit.
Ordering Information
Part Number
Description
QPO-2-EVAL1
Evaluation board for QPO-2LZ
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
Picor Corporation • www.picorpower.com • QPO-2-EVAL1 Data Sheet
Email
Vicor Express: [email protected]
Technical Support: [email protected]
P/N 30642
Rev. 1.2
4/09