sx8643 Semtech Corporation, sx8643 Datasheet - Page 41

• Manufacturer Part Number: sx8643
• Description: Ultra Low Power, Capacitive Button Touch Controller 12 Sensors With Enhanced Led Drivers
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
CapModeMisc
CapMode11_8, CapMode7_4, CapMode3_0:
Revision 7_5, February 10
Capacitive Sensors Parameters
Address
0x1A
0x1B
0x1C
0x1D
0x1E
0x1F
By default the ASI is using a common sensitivity for all capacitive sensors as in the usual case overlay material
and sensors sizes are about equal. The register bits CapSensitivity0_1[7:4] determine the sensitivity for all
sensors in common sensitivity mode.
In special applications it might be required to have a different, individual, sensitivity for each CAP pin. This can
be obtained by setting bit CapModeMisc[2]. The individual sensitivity mode results in longer sensing periods
than required in common sensitivity mode.
The CAP pins can be set as a button or disabled depending on the application.
Buttons and disabled CAP pins can be attributed freely (examples in Figure 41).
Name
CapThresh7
CapThresh8
CapThresh9
CapThresh10
CapThresh11
CapPerComp
buttons
Bits
7:0
7:0
7:0
7:0
7:0
7:4
3:0
Table 15
Description
CAP7 Touch Threshold
CAP8 Touch Threshold
CAP9 Touch Threshold
CAP10 Touch Threshold
CAP11 Touch Threshold
Reserved
Periodic Offset Compensation
Table 16 Possible
minimum
one
© 2010 Semtech Corp.
Capacitive Sensors Parameters
Ultra Low Power, Capacitive Button Touch Controller
41
CAP pin modes
default
twelve
(12 sensors) with Enhanced LED Drivers
Defines the periodic offset compensation.
0x0: OFF (default)
0x1: 1 second
0x2: 2 seconds
…
0x7: 7 seconds
0x8: 16 seconds
0x9: 18 seconds
…
0xE: 28 seconds
0xF: 60 seconds
maximum
twelve
DATASHEET
www.semtech.com
SX8643