PIC16F883 Microchip Technology Inc., PIC16F883 Datasheet - Page 92

• Manufacturer Part Number: PIC16F883
• Description: 28/40/44-pin Flash-based, 8-bit Cmos Microcontrollers With Nanowatt Technology
• Manufacturer: Microchip Technology Inc.

PIC16F882/883/884/886/887
8.7
A simplified circuit for an analog input is shown in
Figure 8-6. Since the analog input pins share their con-
nection with a digital input, they have reverse biased
ESD protection diodes to V
input, therefore, must be between V
input voltage deviates from this 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 kΩ is recommended
for the analog sources. Also, any external component
connected to an analog input pin, such as a capacitor or
a Zener diode, should have very little leakage current to
minimize inaccuracies introduced.
FIGURE 8-6:
DS41291D-page 90
Analog Input Connection
Considerations
Legend: C
V
A
Rs < 10K
I
R
R
V
V
LEAKAGE
A
T
PIN
IC
S
ANALOG INPUT MODEL
A
DD
IN
= Input Capacitance
= Leakage Current at the pin due to various junctions
= Interconnect Resistance
= Source Impedance
= Analog Voltage
= Threshold Voltage
and V
C
5 pF
PIN
SS
SS
and V
. The analog
V
DD
DD
. If the
V
V
T
T
Preliminary
≈ 0.6V
≈ 0.6V
Note 1: When reading a PORT register, all pins
I
±500 nA
Vss
LEAKAGE
2: Analog levels on any pin defined as a
R
configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
convert as an analog input, according to
the input specification.
digital input, may cause the input buffer to
consume more current than is specified.
IC
© 2007 Microchip Technology Inc.
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