PIC16F785-I/P Microchip Technology Inc., PIC16F785-I/P Datasheet - Page 72

• Manufacturer Part Number: PIC16F785-I/P
• Description: MCU, 8-Bit, 2KW Flash, 128 RAM, 18 I/O, DIP-20
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F785-I/P

• A/d Inputs: 12-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 17
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 20-pin PDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

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