78

Features

s Reduces Output Ripple to <3 mV pp

s Compatible with any VI-200/VI-J00-

based Product: 5 to 50Vdc Output

s Full Attenuation Up to 20A

s No Adjustments Required

s 93-99% Efficiency

s Converter Sense, Trim, Overvoltage

and Overcurrent Retained

s Size: 2.28" x 2.4" x 0.5"

(57,9 x 61,0 x 12,7)

s 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

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

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

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.

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.

with sense leads connected, the VI-RAM will be stable for any non-inductive load.

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