DocID028405 Rev 1
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UM1955
Buffer configuration
28
3 Buffer
configuration
The buffer configuration allows users to connect a high output impedance circuit to a low
input impedance circuit without disturbing the signal. This function is possible thanks to the
high impedance of the operational amplifier input stage and the operational amplifier output
capabilities. The operational amplifier used for this configuration is the TSV734, which has a
minimum output current of 40 mA.
3.1
How to set up the board
In order to use the buffer configuration on the expansion board, users simply connect their
signal to the “in” pin on the buffer section of the board. The output signal can be retrieved on
the “out” pin in the same board section. The output voltage of the operational amplifier is not
intended to be connected to any microcontroller input on the expansion board since this
configuration is most often used before another circuit.
3.2 Theoretical
output
The output voltage of the operational amplifier is equal to its input voltage:
V
out
=V
in
Note that this equation is correct as long as the input voltage stays between 0 V and 3.3 V
(the power supply voltage of the operational amplifier).
