Initial Configuration - Texas Instruments VCA8613EVM User Manual

Description
1 Description
The VCA861xEVM is designed to provide ease of use in evaluating the
performance of the VCA8613 variable gain amplifier. The evaluation module
operates in three modes: Stand-Alone, PC-Control, and Direct-Control.
Stand-Alone mode uses an onboard microcontroller to enable the operation
of the VCA8613. The functionality in Stand-Alone mode is limited to
factory-programmed modes. PC-Control mode uses the included software to
operate all of the functions of the VCA8613. The software was written on
Windows2000 and its operation has been verified with Windows XP,
Windows2000, and Windows98. Direct-Control mode uses external control
and data signals to control the functions of the VCA8613.
The VCA8613EVM has the following features:
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2

Initial Configuration

2.1 Power Supply
The VCA861xEVM has provisions for three separate power supplies:
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1)
The +3V input allows the VCA to be powered separately from the rest of the
evaluation module for supply current monitoring of the VCA only.
2
Easy testing of the VCA8613
Single-ended input
Three modes of operation
J
Stand-Alone
J
PC-Control
J
Direct-Control
Separately adjustable attenuation and gain ranges in PC-Control mode
+5V: Positive Supply with Integrated VCA Supply
−5V: Negative Supply for Output and CW Amplifiers
(1)
+3V: Positive VCA Supply
This positive VCA supply is not used when R1 is populated with a 0Ω resistor. If this supply
is used, then R1 must be removed.
(1)