DocID028405 Rev 1

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UM1955

Buffer configuration

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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:

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).