FAAQs and answers

TN0235

4/9

Doc ID 17218 Rev 1

2.3

What are the main features and benefits of the STM8T141

solution?

●

Single channel capacitive sensor for touch or proximity detection with four user

configurable sensitivity levels to accommodate different dielectric panel thicknesses

and materials.

●

One configurable output to report touch or proximity detection (active, toggle and latch

modes).

●

Compact 8-pin package: UFDFPN8 (3 x 2 mm) or SO8 narrow

●

On-chip voltage regulator to enhance the detection sensitivity and stability while

offering high-level immunity against noise.

●

Four selectable power modes including 11µA in extreme low power mode and 30 µA in

normal mode.

●

2.0 V to 5.5 V voltage range suitable for most battery powered applications.

●

Environment compensation filter and automatic calibration. There is no need for

production line calibration or user calibration.

●

Built-in driven shield function to enhance proximity detection and protect sensing

electrode from noise.

●

Detection timeout resets the output state after a configurable period of activation (15 s,

45 s, or infinite). This allows the device to recover from false detection due to drastic

changes in the surroundings.

2.4

What is the driven shield feature designed for?

When powered with 4.5 V or more, the STM8T141 offers a built-in shielding function. It

allows the sensing electrode to be placed at a distance from electronics or protects the

electrode from unwanted environmental interference. The shield principle consists of

actively driving the shield plane or element with the same signal waveform as the electrode

one. It significantly reduces the impact of the capacitance electrode/shield on the sensed

result.

2.5

Is a specific calibration required in the production of the

application or during its lifetime?

The device calibrates when powered up thus it compensates for any process variations

during the production cycle (for example, panel thickness variation between different

production lots).

Over time, the device also adapts automatically its own internal reference values to

compensate for any changes in power supply, temperature, and moisture.