sx8636 Semtech Corporation, sx8636 Datasheet - Page 41

• Manufacturer Part Number: sx8636
• Description: Low Power, Capacitive Button Touch Controller 8 Sensors With Enhanced Led Drivers And Proximity Sensing
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
CapModeMisc
CapMode7_4, CapMode3_0:
Revision 7_5, September 10
Capacitive Sensors Parameters
Address
0x1F
0x70
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.
It might be required to have a different, individual, sensitivity for each CAP pin (for example proximity sensor
set to max sensitivity while touch sensors are set to a lower one). This can be obtained by setting
CapModeMisc[2:0] to “100” 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). All buttons can be used for
touch or proximity sensing, in the latter case register CapProxEnable needs to be set accordingly.
Name
CapPerComp
CapProxEnable
buttons
Bits
7:4
3:0
7:0
Table 15
Description
Reserved
Periodic Offset Compensation
Enables proximity sensing:
0x46: OFF
0x74: ON
Table 16 Possible
minimum
one
© 2010 Semtech Corp.
Low Power, Capacitive Button Touch Controller (8 sensors)
Capacitive Sensors Parameters
with Enhanced LED Drivers and Proximity Sensing
41
CAP pin modes
default
eight
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
eight
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SX8636