PIC16F946T-I/PT Microchip Technology, PIC16F946T-I/PT Datasheet - Page 102

• Manufacturer Part Number: PIC16F946T-I/PT
• Description: Microcontroller
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F946T-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 336 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MA160011 - DAUGHTER BOARD PICDEM LCD 16F91X
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC16F946
8.6
The Comparator module also allows the selection of an
internally generated voltage reference for one of the
comparator inputs. The VRCON register, Register 8-3,
controls the voltage reference module shown in
Figure 8-6.
8.6.1
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 8-1:
FIGURE 8-6:
DS41265A-page 100
VRR = 1 (low range): CV
VRR = 0 (high range):
V
DD
Comparator
Comparator Reference
CV
CV
CONFIGURING THE VOLTAGE
REFERENCE
REF
REF
VREN
Input
= (V
to
DD
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
/4) + (VR3:VR0 x V
REF
VR<3:0>
= (VR3:VR0/24) x V
16-1 Analog
8R
MUX
DD
V
VR <3:0> = ‘0000’
R
REN
/32)
DD
Preliminary
R
16 Stages
8.6.2
The full range of V
the construction of the module. The transistors on the
top and bottom of the resistor ladder network
(Figure 8-6) keep CV
V
clearing the VREN bit (VRCON<7>). When disabled,
the reference voltage is V
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 Section 19.0 “Electrical
Specifications”.
DD
REF
. The exception is when the module is disabled by
R
output changes with fluctuations in V
VOLTAGE REFERENCE
ACCURACY/ERROR
R
SS
REF
to V
REF
© 2005 Microchip Technology Inc.
DD
module current.
DD
SS
from approaching V
cannot be realized due to
derived and therefore, the
8R
when VR<3:0> = 0000.
VRR
DD
SS
. The
or