PIC12F1822 MICROCHIP [Microchip Technology], PIC12F1822 Datasheet - Page 131

• Manufacturer Part Number: PIC12F1822
• Description: 8/14-Pin Flash Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

14.0
The Fixed Voltage Reference, or FVR, is a stable
voltage reference, independent of V
2.048V or 4.096V selectable output levels. The output
of the FVR can be configured to supply a reference
voltage to the following:
• ADC input channel
• ADC positive reference
• Comparator positive input
• Digital-to-Analog Converter (DAC)
The FVR can be enabled by setting the FVREN bit of
the FVRCON register.
FIGURE 14-1:
 2010 Microchip Technology Inc.
FIXED VOLTAGE REFERENCE
(FVR)
VOLTAGE REFERENCE BLOCK DIAGRAM
CDAFVR<1:0>
ADFVR<1:0>
FVRRDY
FVREN
DD
, with 1.024V,
2
2
PIC12F/LF1822/16F/LF1823
+
_
Preliminary
X
X
X
X
X
X
1.024V Fixed
Reference
1
2
4
1
2
4
14.1
The output of the FVR supplied to the ADC,
Comparators, and DAC is routed through two
independent programmable gain amplifiers. Each
amplifier can be configured to amplify the reference
voltage by 1x, 2x or 4x, to produce the three possible
voltage levels.
The ADFVR<1:0> bits of the FVRCON register are
used to enable and configure the gain amplifier settings
for the reference supplied to the ADC module. Refer-
ence Section 15.0 “Analog-to-Digital Converter
(ADC) Module” for additional information.
The CDAFVR<1:0> bits of the FVRCON register are
used to enable and configure the gain amplifier settings
for the reference supplied to the DAC and comparator
module. Reference Section 16.0 “Digital-to-Analog
Converter (DAC) Module” and Section 18.0 “Com-
parator Module” for additional information.
14.2
When the Fixed Voltage Reference module is enabled, it
requires time for the reference and amplifier circuits to
stabilize. Once the circuits stabilize and are ready for use,
the FVRRDY bit of the FVRCON register will be set. See
Section 29.0 “Electrical Specifications” for the
minimum delay requirement.
Independent Gain Amplifiers
FVR Stabilization Period
(To Comparators, DAC)
(To ADC Module)
FVR BUFFER1
FVR BUFFER2
DS41413A-page 131