SX8644EVK Semtech, SX8644EVK Datasheet - Page 14

Manufacturer Part Number

SX8644EVK

Description

Manufacturer

Semtech

Datasheet

1.SX8644EVK.pdf (76 pages)

Lead Free Status / RoHS Status

Not Compliant

SX8644

Ultra Low Power, Capacitive Button and Slider

Touch Controller (12 sensors) with Enhanced LED Drivers

ADVANCED COMMUNICATIONS & SENSING

DATASHEET

3.5 Sensors on the PCB

The capacitive sensors are relatively simple copper areas on the PCB connected to the twelve SX8644 capacitive

sensor input pins (CAP0…CAP11).The sensors are covered by isolating overlay material (typically 1mm...3mm).

The area of a sensor is typically one square centimeter which corresponds about to the area of a finger touching

the overlay material.

The capacitive sensors can be setup as ON/OFF buttons (see example Figure 9) or arranged in a slider

configuration (see example Figure 10) for e.g. menu scrolling or volume control applications.

layer of four sensors for buttons

Figure 9 PCB top

(surrounded by a ground plane)

PCB top layer of one slider using six sensors

Figure 10

(surrounded by ground plane)

Revision 7_3, January 10