Datasheet

 2011 Microchip Technology Inc. Preliminary DS41585A-page 85
PIC10(L)F320/322
12.0 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
The FVR can be enabled by setting the FVREN bit of
the FVRCON register.
12.1 Independent Gain Amplifiers
The output of the FVR supplied to the ADC is routed
through an independent programmable gain amplifier.
The 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.
12.2 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 24.0 “Electrical Specifications” for the
minimum delay requirement.
FIGURE 12-1: VOLTAGE REFERENCE BLOCK DIAGRAM
FVR
(To ADC Module)
x1
x2
x4
+
-
1.024V Fixed
Reference
FVREN
FVRRDY
2
ADFVR<1:0>
Any peripheral requiring
the Fixed Reference
(See Table 12-1)
TABLE 12-1: PERIPHERALS REQUIRING THE FIXED VOLTAGE REFERENCE (FVR)
Peripheral Conditions Description
HFINTOSC FOSC = 1 EC on CLKIN pin.
BOR
BOREN<1:0> = 11 BOR always enabled.
BOREN<1:0> = 10 and BORFS = 1 BOR disabled in Sleep mode, BOR Fast Start enabled.
BOREN<1:0> = 01 and BORFS = 1 BOR under software control, BOR Fast Start enabled.
IVR All PIC10F320/322 devices, when
VREGPM1 = 1 and not in Sleep
The device runs off of the Power-Save mode regulator when
in Sleep mode.