PIC18F23K20-E/MLQTP MICROCHIP [Microchip Technology], PIC18F23K20-E/MLQTP Datasheet - Page 278

• Manufacturer Part Number: PIC18F23K20-E/MLQTP
• Description: 28/40/44-Pin Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F2XK20/4XK20
20.7
A simplified circuit for an analog input is shown in
Figure 20-6. Since the analog input pins share their
connection with a digital input, they have reverse
biased ESD protection diodes to V
analog input, therefore, must be between V
If the 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 20-6:
DS41303B-page 276
Analog Input Connection
Considerations
Legend: C
V
Note 1: See Section 26.0 “Electrical Characteristics”.
A
Rs < 10K
I
R
R
V
V
LEAKAGE
A
T
PIN
IC
S
ANALOG INPUT MODEL
A
IN
= Input Capacitance
= Leakage Current at the pin due to various junctions
= Interconnect Resistance
= Source Impedance
= Analog Voltage
= Threshold Voltage
C
5 pF
PIN
DD
and V
SS
Advance Information
V
and V
SS
DD
V
. The
V
T
T
DD
≈ 0.6V
≈ 0.6V
.
Note 1: When reading a PORT register, all pins
I
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
(1)
© 2007 Microchip Technology Inc.