Datasheet

 2011-2013 Microchip Technology Inc. DS40001453E-page 317
PIC16(L)F1847
27.0 CAPACITIVE SENSING
MODULE
The Capacitive Sensing (CPS) module allows for an
interaction with an end user without a mechanical
interface. In a typical application, the CPS module is
attached to a pad on a Printed Circuit Board (PCB),
which is electrically isolated from the end user. When the
end user places their finger over the PCB pad, a
capacitive load is added, causing a frequency shift in the
CPS module. The CPS module requires software and at
least one timer resource to determine the change in
frequency. Key features of this module include:
• Analog MUX for monitoring multiple inputs
• Capacitive sensing oscillator
• Multiple Power modes
• High power range with variable voltage references
• Multiple timer resources
• Software control
• Operation during Sleep
FIGURE 27-1: CAPACITIVE SENSING BLOCK DIAGRAM
TMR0CS
Capacitive
Sensing
Oscillator
CPSOSC
CPSON
CPSRNG<1:0>
TMR0
0
1
Set
TMR0IF
Overflow
T0XCS
0
1
T0CKI
CPSOUT
CPSCLK
F
OSC/4
Timer0 Module
T1CS<1:0>
T1OSC/
T1CKI
TMR1H:TMR1L
EN
T1GSEL<1:0>
Timer1 Gate
Control Logic
T1G
F
OSC
FOSC/4
Timer1 Module
sync_C1OUT
sync_C2OUT
0
1
Int.
Ref.
FVR
DAC
Ref+
Ref-
CPSRM
0
1
CPS0
CPS1
CPS2
CPS3
CPS4
CPS5
CPS6
CPS7
CPS8
CPS9
CPS10
CPSCH<3:0>
CPS11
CPSON
(1)
Note 1: If CPSON = 0, disabling capacitive sensing, no channel is selected.