PIC16HV785 Microchip Technology Inc., PIC16HV785 Datasheet - Page 72

• Manufacturer Part Number: PIC16HV785
• Description: 20-pin Flash-based 8-bit Cmos Microcontroller
• Manufacturer: Microchip Technology Inc.

PIC16F785/HV785
10.0
There are two voltage references available in the
PIC16F785/HV785: The voltage referred to as the
comparator reference (CV
based on V
ence (VR) is a fixed voltage derived from a stable band
gap source. Each source may be individually routed
internally to the comparators or output, buffered or
unbuffered, on the RA1/AN1/C12IN0-/V
pin.
10.1
The comparator module also allows the selection of an
internally generated voltage reference for one of the
comparator inputs. The VRCON register (Register 10-1)
controls the voltage reference module shown in
Figure 10-1.
DS41249D-page 70
VOLTAGE REFERENCES
Comparator Reference
DD
; The voltage referred to as the VR refer-
REF
) is a variable voltage
REF
/ICSPCLK
Preliminary
10.1.1
The voltage reference can output 32 distinct voltage
levels, 16 in a high range and 16 in a low range.
The following equation determines the output voltages:
EQUATION 10-1:
10.1.2
The full range of V
the construction of the module. The transistors on the
top and bottom of the resistor ladder network
(Figure 10-1) keep CV
V
clearing all CVROE, C1VREN and C2VREN bits. When
disabled, the reference voltage is V
is ‘0000’ and the VRR (VRCON<5>) bit is set. This
allows the comparators to detect a zero-crossing and
not consume CV
The voltage reference is V
CV
tested absolute accuracy of the comparator voltage
reference can be found in Table 19-8.
DD
V
V
REF
RR
RR
. The exception is when the module is disabled by
= 1 (low range):
= 0 (high range):
output changes with fluctuations in V
CV
CV
CONFIGURING THE VOLTAGE
REFERENCE
VOLTAGE REFERENCE
ACCURACY/ERROR
REF
REF
REF
= (V
SS
= VR<3:0> x V
module current.
to V
CV
DD
REF
© 2006 Microchip Technology Inc.
DD
DD
REF
/4) + (VR<3:0> x V
from approaching V
derived and therefore, the
cannot be realized due to
OUTPUT VOLTAGE
DD
SS
/24
when VR<3:0>
DD
DD
SS
. The
/32)
or