Digilent VRM - Manual

D D i i g g i i l l e e n n t t V V R R M M R R e e f f e e r r e e n n c c e e M M a a n n u u a a l l
Revision: August 17, 2010
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Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners.
Overview
The Digilent VRM (Voltage Regulator Module)
is a battery-friendly switching voltage regulator
capable of providing up to 6A of current at 5V
or 3.3V. The input voltage can be stepped
down from sources as high as 15V. It is ideal
for use in mechatronics applications to
efficiently regulate battery voltage, or in any
application where a clean step down is
required.
Features include:
•
up to 6A synchronous step down
switching regulator
•
selectable 5V or 3.3V output voltage
•
input voltage range of 5-15V
•
479kHz internal switching frequency
•
switching synchronization to an
external clock.
Functional Description
The Digilent VRM is designed to provide
regulated 5V or 3.3V power using an external
power source such as a battery. The 6A
maximum current is ideal for application from
small control boards to large mechatronics
projects. In particular, it is useful for projects
utilizing Digilent boards requiring a 5V source,
as both the 5V external rail and the 3.3V
internal regulation can be achieved.
Note: The 6A output current rating depends on
operating temperature. It may be necessary to
provide additional heat sinking or fan cooling to
achieve the full 6A output current in some
situations.
The VRM uses a Texas Instruments
TPS54620 switching regulator. Refer to the
data sheet available from Texas Instruments
for detailed information about this regulator.
The schematic for the VRM is available on the
Digilent web site. Refer to the schematic for
detailed information about the circuitry on the
board and the input, output, and configuration
connections on the board.
Input and Output Connections
The VRM board has power inputs and outputs
in both screw terminal and two-pin header
format. Connect the external power source to
the connections labeled “GND” and “VU” on
the screw terminal connector J6, or the two-pin
header, J3, labeled “BATTERY”. Observe
proper polarity in making the connections, as
reversed polarity will damage the VRM.
Digilent has battery packs available with
connectors suitable for the two-pin header.
Note: the screw terminal connector J6 is rated
for up to 10A of current but the two pin header
J3 is only rated for 2A. Do not use the VRM in
configurations where more than 2A of input
current will pass through J3.
Board Circuit Diagram