DV164136 Microchip Technology, DV164136 Datasheet - Page 306

• Manufacturer Part Number: DV164136
• Description: DEVELOPMENT KIT FOR PIC18
• Manufacturer: Microchip Technology
• Series: PIC®r
• Type: MCUr

Specifications of DV164136

• Contents: Board, Cables, CDs, PICkit™ 3 Programmer, Power Supply
• Processor To Be Evaluated: PIC18F8722, PIC18F87J11
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3.3 V, 5 V
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18F8xxx
• Kit Contents: PIC18 Exp Brd PICkit 3 Cable CD PSU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PIC18F8722, PIC18F87J11
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F87J11 FAMILY
22.2
A single comparator is shown in Figure 22-2, 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 22-2 represent
the uncertainty due to input offsets and response time.
FIGURE 22-2:
FIGURE 22-3:
DS39778D-page 306
V
V
Output
IN
IN
-
+
V
V
IN
IN
Comparator Operation
+
-
VA
R
S
Legend:
+
–
< 10k
SINGLE COMPARATOR
COMPARATOR ANALOG INPUT MODEL
IN
-, the output of the comparator
A
IN
C
V
I
R
R
VA
LEAKAGE
IN
C
5 pF
PIN
T
IC
S
-, the output of the
PIN
Output
= Input Capacitance
= Threshold Voltage
= Leakage Current at the pin due to various junctions
= Interconnect Resistance
= Source Impedance
= Analog Voltage
IN
+ is less
IN
+ is
V
DD
V
V
T
T
= 0.6V
= 0.6V
22.3
Response time is the minimum time, after selecting a
new reference voltage or input source, before the com-
parator output has a valid level. The response time of
the comparator differs from the settling time of the volt-
age reference. Therefore, both of these times must be
considered when determining the total response to a
comparator input change. Otherwise, the maximum
delay of the comparators should be used (see
Section 27.0 “Electrical Characteristics”).
22.4
A simplified circuit for an analog input is shown in
Figure 22-3. Since the analog pins are connected to a
digital output, they have reverse biased diodes to V
and V
V
range by more than 0.6V in either direction, one of the
diodes is forward biased and a latch-up condition may
occur. A maximum source impedance of 10 kΩ is
recommended for the analog sources. Any external
component connected to an analog input pin, such as
a capacitor or a Zener diode, should have very little
leakage current.
SS
and V
SS
. The analog input, therefore, must be between
Comparator Response Time
Analog Input Connection
Considerations
I
±500 nA
V
LEAKAGE
DD
SS
. If the input voltage deviates from this
R
IC
© 2009 Microchip Technology Inc.
Comparator
Input
DD