AN2869 datasheet(23/43 Pages) STMICROELECTRONICS

部件名	AN2869

功能描述	Guidelines for designing touch sensing applications

PDF	43 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

标志

23 / 43 page

AN2869

Surface electrode design

Doc ID 15298 Rev 6

23/43

Figure 16.

Interlaced patterned rotary sensor

3.4.3

Rotary sensor with central touchkey

It is possible to locate a touchkey in the centre of a rotary sensor. This touchkey has a lower

sensitivity compared to other single keys. To reduce the loss of sensitivity induced by the

center key on the rotary sensor, it is recommended to place the center key and rotary sensor

electrodes on the same acquisition bank. The pattern of the central key must be as

symmetrical as possible so that the loading effect on the rotary sensor is also symmetrical.

ai15093

0.2 - 0.3 mm

Full band width 2.0 - 4.0 mm

Tooth pitch

2.0 - 4.0 mm

2 mm

LEGEND:

Via between layers

10 % meshed ground plane

Copper electrode

AN2869 数据表(PDF) 23 Page - STMicroelectronics