®
QPO-2L
QuietPower™
QPO-2L Low Voltage Output Ripple Attenuator
Description
Features of the QPO-2
The QPO-2 output ripple attenuator SiP uses active
filtering to reduce supply output ripple and noise
(PARD) by over 30dB from 1kHz to 500kHz. The
QPO-2 is biased through the VAUX input and filters
an input voltage range of 0.3VDC to 5.5VDC while
supporting load currents as high as 20A. The VAUX
input range is 7V to 12V with a minimum required
difference between VAUX and QPO OUT of 7V.
Output regulation is maintained by using either the
remote sense or the trim adjustment of the power
supply. The product can be used in an open loop
configuration when ripple and noise reduction are
the main objective and load regulation is not as
critical. The QPO-2 architecture improves transient
response and ensures quiet point-of-load regulation
when used with most switching power supplies. The
performance waveform in figure 2 is an example of
the ripple reduction and transient load
improvement the QPO-2 can provide using a 3.3V
brick style converter.
• >30 dB PARD attenuation, 1kHz to 500kHz
• >20 dB PARD attenuation, 50Hz to 500Hz (1)
• 20A rating over a 0.3-5.5Vdc operating range
• Supports precise point-of load regulation
• 90-95% efficiency with load vs. headroom trim
• User selectable performance optimization of the
attenuation, power dissipation & transient load
response
• Peak detector function optimizes headroom for
ripple amplitude variation automatically
• 25 x 25 x 4.5 mm SiP with LGA mounting
• Closed loop control improves transient response
of most DC/DC converters and power supplies
• Reduces required number of output capacitors to
support dynamic loads.
• Patents Pending
Applications
Note 1: For off-line supplies 20dB attenuation can be achieved
down to 50Hz with additional capacitance added from the VREF
pin to REFGND.
•
•
•
Distributed Point of Load Power Systems
Sensors Requiring Low Noise Power
Medical Instrumentation
Typical Application
QPO-2 Performance
VAUX
QPO IN (AC)
VAUX
LOAD+
QPO IN
QPO OUT
VOUT+
PEAK IN
CIN*
SENSE+
Rsc
RCP
QPO-2L
RCLAMP
ADJUST
RSL
SC SET
+TRIM
QPO OUT (AC)
CSC
RSA
LOAD CURRENT
SENSE-
VOUT-
RHR
*Optional
LOAD-
Figure 1 – ADJUST/Trim supports applications that don’t
Figure 2 – Typical performance with a 3.3 Volt converter,
require remote sense.
showing 1 to 10 A load step.
Picor Corporation • www.picorpower.com
QPO-2L Data Sheet Rev. 1.1 Page 1 of 12