VI-RAM™/VE-RAM™ Rev 1.8 vicorpower.com
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Ripple Attenuator Modules
Ripple Attenuator Modules
VI-RAM™/VE-RAM™
Features & Benefits
• RoHS compliant (VE versions)
• Reduces output ripple to <3mVp-p
• Compatible with any VI-200/VI-J00
based product: 5 to 50VDC output
• Full attenuation up to 20A
• No adjustments required
• 93 – 99% efficiency
• Converter sense, trim, overvoltage
and overcurrent retained
• Size: 2.28” x 2.4” x 0.5”
(57,9 x 61,0 x 12,7 mm)
• CE Mark
Product Highlights
Ripple attenuator modules may be connected
to VI-200 or VI-J00 converters, FlatPACs,
ComPACs or MegaModules, with output
voltages from 5 – 50V, to limit output noise
to less than 3mV peak-to-peak at loads
up to 20A. Combining active and passive
filtering, the VI-RAM attenuates both low
frequency input power source fundamental
and harmonics, as well as high frequency
switching components in the frequency
range of DC to 20MHz, while exhibiting
efficiencies of 93-99%. No adjustments
are required, and remote sense and output
voltage trim features are retained.
A member of Vicor’s high-power density,
high performance, component-level
power building blocks, the VI-RAM offers
the power systems architect a single,
flexible, component-level solution to almost
any “clean power” problem. At the same
time, the VI-RAM eliminates the space,
efficiency, and weight penalties associated
with linear power sources, and the stability,
efficiency, and adjustment penalties
associated with external “add on” filters for
conventional switchers.
VI-RAM Specifications
Parameter Min. Typ. Max. Remarks
Output Noise & Ripple
VI-200 3mVp-p From 10% of full rated
VI-J00 10mVp-p output current of the
source converter to full load
Input Voltage Range 5VDC 50VDC
Output Voltage Deviation 0.5% From the output voltage
of the VI-200 source to
which the VI-RAM will be
connected
Full Load Current 10A E1, C1, I1 or M1
20A E2, C2, I2 or M2
Overload Current 30A At max. operating baseplate
temperature
DC Voltage Drop 0.34VDC 0.41VDC Up to 10A
0.34VDC 0.44VDC Up to 20A
0.34VDC 0.75VDC Up to 30A (overload)
Dissipation = (DC voltage drop) x (Load current + 15mA)
Isolation 500VRMS Input/Output to baseplate
Size 2.28” x 2.4” x 0.5” SlimMod and FinMod
(57,9 x 61,0 x 12,7) packages available
Weight
E,C-Grade 3.0(85)
I,M-Grade 3.6(102) 3.7(105) 3.8(107) Ounces(Grams)
Parameter (Up to 10A) VI-RAM-E1 VI-RAM-C1 VI-RAM-I1 VI-RAM-M1
(Up to 20A) VI-RAM-E2 VI-RAM-C2 VI-RAM-I2 VI-RAM-M2
Storage Temp. -20°C to +105°C -40°C to +105°C -55°C to +105°C -65°C to +105°C
Operating Temp. -10°C to +100° -25°C to +100°C -40°C to +100°C -55°C to +100°C
(Baseplate)
Product Grade Specifications
Transient Response and Dynamic Range: Full rated noise attenuation will be
maintained at the VI-RAM output for step load changes up to 10% of the rated
output current of the source converter, with the VI-RAM exhibiting an underdamped
output excursion of less than 10mVp-p. Some degradation in noise attenuation during
the transient response period following the step may be exhibited for larger load
changes. Adding output capacitance to the VI-RAM will improve the rejection over a
larger dynamic range.
Sense Connection: Sense -IN and Sense -OUT connections are provided on the VI-RAM.
Sense -IN connections must be connected to the corresponding sense connections on the
Vicor converter. Sense -OUT pins on the VI-RAM must be connected between the
VI-RAM power-output pins and the point of load.
Output Load Characteristics: When used in combination with Vicor DC-DC converters,
and with sense leads connected, the VI-RAM will be stable for any non-inductive load.
DC Voltage Drop: Below full load, the input to output DC Voltage Drop is controlled to
be an essentially constant voltage which appears between the –IN and –OUT terminals.
In overload the DC voltage drop will rise as current increases. A few tens of millivolts
appears between the +IN and +OUT terminals. Care should be taken not to connect IN
and OUT terminals (i.e. through scope probe returns, grounds, etc.), as attenuation will be
adversely affected.
Electrical Considerations
VI-RAM™/VE-RAM™ Rev 1.8 vicorpower.com
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VI-RAM™/VE-RAM™
Input to the converter 10V/cm
Output from the RAM 20mV/cm
60db
55db
25db
30db
35db
40db
45db
50db
10MHz1MHz100KHz10KHz1KHz
100Hz
10Hz
Frequency
Attenuation
Attenuation vs. Frequency (Typical)
VI-200
+OUT
–OUT
– S
+ S
+ IN
– In
Trim
+
–
+ IN
– IN
+OUT
–OUT
+ S OUT
+ S IN
– S OUT
– S IN
N/C
VI-RAM Load
L1
Gate IN
Gate OUT
.01µF
.01µF
.01µF
.01µF
220µF
C1
+
0.22µF
Recommended Connection Diagram
For important application information please refer to the Design Guide and Applications Manual for VI-200 and VI-J00 Family.
Comparison of Input to Output Ripple (Typical)
VI-RAM™/VE-RAM™ Rev 1.8 vicorpower.com
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VI-RAM™/VE-RAM™
5
6
7
8
9
4
3
2
1
0.080 Dia (2) places
Solder plate
over copper alloy
0.040 (1,0) Dia (7) places
Solder plate
over copper alloy
.01
Aluminum Base
Product ID
this surface
Function
+IN
–IN
+OUT
NC
–Sense
–OUT
Pin #
1
2
3
4
5
6
7
8
9
FULL R
+.030 (0,76)
-.000 (0,00)
(5,6) Min.
(7,6) Min. 1.75 Max.
2.40
(57,9)
.12
(12,7)
(48,3)
0.65
(16,5)
0.49
(12,4)
0.300.015
(7,6)(0,38)
.15
2.10
(53,4)
1.30
.40
(10,2)
.35 .015
(8,9)(0,38)
1.40
(35,6)
1.00
(25,4)
.70
(17,8)
+Sense IN
–Sense IN
+Sense
VI-RAM Mechanical Diagram
VI-RAM
2.28
(33,0)
(3,8)
.15
(3,8)
1.90
0.22
.50
(3,0)
(61,0)
.30
(44,4)
Standard
0.080 Dia (2) places
Matte tin over copper
alloy
RoHS
Standard
0.040 (1,0) Dia (7) places
Matte tin over copper
alloy
RoHS
Mechanical Drawing
Storage
Vicor products, when not installed in customer units, should be stored in ESD safe packaging in accordance with ANSI/ESD S20.20,
“Protection of Electrical and Electronic Parts, Assemblies and Equipment” and should be maintained in a temperature controlled factory/
warehouse environment not exposed to outside elements controlled between the temperature ranges of 15°C and 38°C. Humidity shall not
be condensing, no minimum humidity when stored in an ESD compliant package.
VI-RAM™/VE-RAM™ Rev 1.8 vicorpower.com
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VI-RAM™/VE-RAM™
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
makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication. Vicor reserves
the right to make changes to any products, specifications, and product descriptions at any time without notice. Information published by
Vicor has been checked and is believed to be accurate at the time it was printed; however, Vicor assumes no responsibility for inaccuracies.
Testing and other quality controls are used to the extent Vicor deems necessary to support Vicor’s product warranty. Except where
mandated by government requirements, testing of all parameters of each product is not necessarily performed.
Specifications are subject to change without notice.
Visit http://www.vicorpower.com/ram for the latest product information.
Vicor’s Standard Terms and Conditions and Product Warranty
All sales are subject to Vicor’s Standard Terms and Conditions of Sale, and Product Warranty which are available on Vicor’s webpage
(http://www.vicorpower.com/termsconditionswarranty) or upon request.
Life Support Policy
VICOR’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE
EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL COUNSEL OF VICOR CORPORATION. As used
herein, life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and
whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to
result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform
can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. Per Vicor Terms
and Conditions of Sale, the user of Vicor products and components in life support applications assumes all risks of such use and indemnifies
Vicor against all liability and damages.
Intellectual Property Notice
Vicor and its subsidiaries own Intellectual Property (including issued U.S. and Foreign Patents and pending patent applications) relating
to the products described in this data sheet. No license, whether express, implied, or arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Interested parties should contact Vicor’s Intellectual Property Department.
Vicor Corporation
25 Frontage Road
Andover, MA, USA 01810
Tel: 800-735-6200
Fax: 978-475-6715
email
Customer Service: custserv@vicorpower.com
Technical Support: apps@vicorpower.com
