VI-RAM™/VE-RAM™ Rev 1.8 vicorpower.com
Page 1 of 4 06/2017 800 927.9474
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