Microchip Technology AC244049 Data Sheet
PIC16(L)F1825/1829
DS41440C-page 324
2010-2012 Microchip Technology Inc.
27.4
Power Modes
The capacitive sensing oscillator can operate in one of
seven different power modes. The power modes are
separated into two ranges; the low range and the high
range.
When the oscillator’s low range is selected, the fixed
internal voltage references of the capacitive sensing
oscillator are being used. When the oscillator’s high
range is selected, the variable voltage references
supplied by the FVR and DAC modules are being used.
Selection between the voltage references is controlled
by the CPSRM bit of the CPSCON0 register. See
seven different power modes. The power modes are
separated into two ranges; the low range and the high
range.
When the oscillator’s low range is selected, the fixed
internal voltage references of the capacitive sensing
oscillator are being used. When the oscillator’s high
range is selected, the variable voltage references
supplied by the FVR and DAC modules are being used.
Selection between the voltage references is controlled
by the CPSRM bit of the CPSCON0 register. See
for more
information.
Within each range there are three distinct Power modes;
low, medium and high. Current consumption is dependent
upon the range and mode selected. Selecting Power
modes within each range is accomplished by configuring
the CPSRNG <1:0> bits in the CPSCON0 register. See
Within each range there are three distinct Power modes;
low, medium and high. Current consumption is dependent
upon the range and mode selected. Selecting Power
modes within each range is accomplished by configuring
the CPSRNG <1:0> bits in the CPSCON0 register. See
for proper Power mode selection.
The remaining mode is a Noise Detection mode that
resides within the high range. The Noise Detection
mode is unique in that it disables the sinking and
sourcing of current on the analog pin but leaves the rest
of the oscillator circuitry active. This reduces the
oscillation frequency on the analog pin to zero and also
greatly reduces the current consumed by the oscillator
module.
When noise is introduced onto the pin, the oscillator is
driven at the frequency determined by the noise. This
produces a detectable signal at the comparator output,
indicating the presence of activity on the pin.
resides within the high range. The Noise Detection
mode is unique in that it disables the sinking and
sourcing of current on the analog pin but leaves the rest
of the oscillator circuitry active. This reduces the
oscillation frequency on the analog pin to zero and also
greatly reduces the current consumed by the oscillator
module.
When noise is introduced onto the pin, the oscillator is
driven at the frequency determined by the noise. This
produces a detectable signal at the comparator output,
indicating the presence of activity on the pin.
shows a more detailed drawing of the
current sources and comparators associated with the
oscillator.
oscillator.
TABLE 27-1:
POWER MODE SELECTION
CPSRM
Range
CPSRNG<1:0>
Mode
Nominal Current
(1)
0
Low
00
Off
0.0
A
01
Low
0.1
A
10
Medium
1.2
A
11
High
18
A
1
High
00
Noise Detection
0.0
A
01
Low
9
A
10
Medium
30
A
11
High
100
A
Note 1:
See
for more information.