PIC12F683-I/MD Microchip Technology Inc., PIC12F683-I/MD Datasheet - Page 50

• Manufacturer Part Number: PIC12F683-I/MD
• Description: 8 PIN, 3.5KB FLASH, 128 RAM, 6 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC12F683-I/MD

• A/d Inputs: 4-Channel, 10-Bit
• Comparators: 1
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Frequency: 20 MHz
• Input Output: 6
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 8-Pin PDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Serial Interface: None
• 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

PIC12F683
8.1
A single comparator is shown in Figure 8-1 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 8-1 represent
the uncertainty due to input offsets and response time.
The polarity of the comparator output can be inverted
by setting the CINV bit (CMCON0<4>). Clearing CINV
results in a non-inverted output. A complete table
showing the output state versus input conditions and
the polarity bit is shown in Table 8-1.
TABLE 8-1:
FIGURE 8-2:
DS41211B-page 48
Note:
Input Conditions
V
V
V
V
IN
IN
IN
IN
Comparator Operation
- > V
- < V
- > V
- < V
To use CIN+ and CIN- pins as analog
inputs, the appropriate bits must be
programmed in the CMCON0 (19h)
register.
VA
Legend:
IN
IN
IN
IN
Rs < 10K
+
+
+
+
OUTPUT STATE VS. INPUT
CONDITIONS
IN
ANALOG INPUT MODEL
-, the output of the comparator
A
IN
C
V
I
R
R
VA
LEAKAGE
T
PIN
IC
S
CINV
IN
C
5 pF
0
0
1
1
PIN
-, the output of the
= Input Capacitance
= Threshold Voltage
= Leakage Current at the pin due to various junctions
= Interconnect Resistance
= Source Impedance
= Analog Voltage
COUT
IN
+ is less
0
1
1
0
IN
+ is
Preliminary
V
DD
V
V
T
T
= 0.6V
= 0.6V
FIGURE 8-1:
8.2
A simplified circuit for an analog input is shown in
Figure 8-2. 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 may occur. A
maximum source impedance of 10 k 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
Output
V
V
Output
Note 1: When reading the GPIO register, all pins
IN
V
IN
V
IN–
IN+
and V
-
+
SS
V
V
IN
IN
. The analog input, therefore, must be between
2: Analog levels on any pin defined as a
Analog Input Connection
Considerations
I
±500 nA
Vss
+
-
LEAKAGE
DD
configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
convert as analog inputs according to the
input specification.
digital input may cause the input buffer to
consume more current than is specified.
. If the input voltage deviates from this
R
IC
+
–
SINGLE COMPARATOR
 2004 Microchip Technology Inc.
Output
DD