PIC18F4580T-I/PT Microchip Technology, PIC18F4580T-I/PT Datasheet - Page 265

• Manufacturer Part Number: PIC18F4580T-I/PT
• Description: IC PIC MCU FLASH 16KX16 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4580T-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

21.2
A single comparator is shown in Figure 21-2, along with
the relationship between the analog input levels and
the digital output. When the analog input at V
than the analog input V
is a digital low level. When the analog input at V
greater than the analog input, V
comparator is a digital high level. The shaded areas of
the output of the comparator in Figure 21-2 represent
the uncertainty, due to input offsets and response time.
21.3
Depending on the comparator operating mode, either
an external or internal voltage reference may be used.
The analog signal present at V
signal at V
is adjusted accordingly (Figure 21-2).
FIGURE 21-2:
21.3.1
When external voltage references are used, the
comparator module can be configured to have the com-
parators operate from the same or different reference
sources. However, threshold detector applications may
require the same reference. The reference signal must
be between V
pin of the comparator(s).
© 2009 Microchip Technology Inc.
V
V
Output
IN
IN
-
+
V
V
IN
IN
Comparator Operation
Comparator Reference
+
-
IN
EXTERNAL REFERENCE SIGNAL
+ and the digital output of the comparator
SS
and V
+
–
IN
SINGLE COMPARATOR
DD
-, the output of the comparator
and can be applied to either
IN
IN
- is compared to the
-, the output of the
Output
IN
PIC18F2480/2580/4480/4580
+ is less
IN
+ is
21.3.2
The comparator module also allows the selection of an
internally generated voltage reference from the com-
parator voltage reference module. This module is
described in more detail in Section 22.0 “Comparator
Voltage Reference Module”.
The internal reference is only available in the mode
where four inputs are multiplexed to two comparators
(CM<2:0> = 110). In this mode, the internal voltage
reference is applied to the V
comparators.
21.4
Response time is the minimum time, after selecting a
new reference voltage or input source, before the
comparator output has a valid level. If the internal
reference is changed, the maximum delay of the
internal voltage reference must be considered when
using
maximum delay of the comparators should be used
(see Section 28.0 “Electrical Characteristics”).
21.5
The comparator outputs are read through the CMCON
register. These bits are read-only. The comparator
outputs may also be directly output to the RE1 and RE2
I/O pins. When enabled, multiplexers in the output path
of the RE1 and RE2 pins will switch and the output of
each pin will be the unsynchronized output of the
comparator.
comparators is related to the input offset voltage and
the response time given in the specifications.
Figure 21-3 shows the comparator output block
diagram.
The TRISE bits will still function as an output enable/
disable for the RE1 and RE2 pins while in this mode.
The polarity of the comparator outputs can be changed
using the C2INV and C1INV bits (CMCON<4:5>).
Note 1: When reading the PORT register, all pins
the
2: Analog levels on any pin defined as a
Comparator Response Time
Comparator Outputs
INTERNAL REFERENCE SIGNAL
configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
convert an analog input according to the
Schmitt Trigger input specification.
digital input may cause the input buffer to
consume more current than is specified.
comparator
The
uncertainty
outputs.
of
DS39637D-page 265
IN
+ pin of both
Otherwise,
each
of
the
the