Datasheet

 2011-2012 Microchip Technology Inc. Preliminary DS41579D-page 143
PIC16(L)F1782/3
15.0 FIXED VOLTAGE REFERENCE
(FVR)
The Fixed Voltage Reference, or FVR, is a stable
voltage reference, independent of V
DD, with 1.024V,
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.
15.1 Independent Gain Amplifiers
The output of the FVR supplied to the ADC,
Comparators, and DAC is routed through two
independent programmable gain amplifiers. Each
amplifier can be programmed for a gain of 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. Reference
Section 19.0 “Digital-to-Analog Converter (DAC)
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 17.0
Section 19.0
“Digital-to-Analog Converter (DAC) Module”
and
Section 20.0 “Comparator Module” for additional
information.
15.2 FVR Stabilization Period
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 30.0 “Electrical Specifications” for the
minimum delay requirement.