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KC V.1
Visitor II
October 18, 2022
Solved

STM32WB55 touch sensing: range of capacitance value?

IN STM32WB55 touch sensing features, at which range of capacitance value touch sensor can be used?

It say few picofarad, do any exact capacitance range for proper working?

if i use a dedicated touch sensor with 100pf nominal value do it will work?

This topic has been closed for replies.
OlivierR
OlivierRBest answer
ST Employee
October 18, 2022

Hello,

We recommend to decrease as much as possible sensor capacitance to speed-up acquisition time.

Increasing sensor capacitance will decrease sensitivity (Delta vs Measure when we used touch sensing middleware).

Usually sensor capacitance is around 10pF.

You can refer to AN5105 for information.

Regards.

1 reply

OlivierR
OlivierRBest answer
ST Employee
October 18, 2022

Hello,

We recommend to decrease as much as possible sensor capacitance to speed-up acquisition time.

Increasing sensor capacitance will decrease sensitivity (Delta vs Measure when we used touch sensing middleware).

Usually sensor capacitance is around 10pF.

You can refer to AN5105 for information.

Regards.