12
1-800-735-6200
78
Features
■ Reduces Output Ripple to <3 mV pp
■ 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)
■ CE Marked
Product Highlights
Ripple attenuator modules may be
connected to VI-200 or VI-J00 converters,
FlatPACs, MegaPACs, MasterModules or
MegaModules, with output voltages from
5 to 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, and high frequency switching
components in the frequency range of DC
to 20 MHz, 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™
Ripple Attenuator
Modules
VI-RAM Specifications
(typical at T
BP
= 25°C, nominal line, 75% load unless otherwise specified)
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)
Parameter Min. Typ. Max. Remarks
Output Noise & Ripple
VI-200 3 mV pp From 10% of full rated
VI-J00 10 mV pp output current of the
source converter to full load
Input Voltage Range 5 Vdc 50 Vdc
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 10Amps E1, C1, I1 or M1
20Amps E2, C2, I2 or M2
Overload Current 30Amps At max. allowable baseplate
temperature
DC Voltage Drop 0.34 0.41 Up to 10Amps
0.34 0.44 Up to 20Amps
0.34 0.75 Up to 30Amps (overload)
Dissipation = (DC voltage drop) x (Load current + 15 mA)
Isolation 500V
RMS
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 3.0 Ounces (85 Grams)
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 10 mV pp.
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
