PIC18LF8720 Microchip Technology, PIC18LF8720 Datasheet - Page 221

• Manufacturer Part Number: PIC18LF8720
• Description: (PIC18LF6620/6520/8520/6620/8620/6720/8720) 64/80-Pin High-Performance / 64-Kbyte Enhanced Flash Microcontrollers
• Manufacturer: Microchip Technology

19.2
The A/D conversion time per bit is defined as T
A/D conversion requires 12 T
The source of the A/D conversion clock is software
selectable. There are seven possible options for T
• 2 T
• 4 T
• 8 T
• 16 T
• 32 T
• 64 T
• Internal RC oscillator
For correct A/D conversions, the A/D conversion clock
(T
of 1.6 s.
Table 19-1 shows the resultant T
the device operating frequencies and the A/D clock
source selected.
TABLE 19-1:
 2004 Microchip Technology Inc.
AD
) must be selected to ensure a minimum T
OSC
OSC
OSC
OSC
OSC
OSC
Selecting the A/D
Conversion Clock
Operation
16 T
32 T
64 T
2 T
4 T
8 T
RC
OSC
OSC
OSC
OSC
OSC
OSC
AD Clock Source (T
PIC18F6520/8520/6620/8620/6720/8720
T
AD
vs. DEVICE OPERATING FREQUENCIES
AD
per 10-bit conversion.
AD
times derived from
ADCS2:ADCS0
AD
)
000
100
001
101
010
110
x11
AD
AD
. The
AD
time
:
19.3
The ADCON1, TRISA, TRISF and TRISH registers
control the operation of the A/D port pins. The port pins
needed as analog inputs must have their correspond-
ing TRIS bits set (input). If the TRIS bit is cleared
(output), the digital output level (V
converted.
The A/D operation is independent of the state of the
CHS3:CHS0 bits and the TRIS bits.
Note 1: When reading the port register, all pins
PIC18FXX20
1.25 MHz
2.50 MHz
5.00 MHz
10.0 MHz
20.0 MHz
40.0 MHz
—
2: Analog levels on any pin defined as a dig-
Configuring Analog Port Pins
Maximum Device Frequency
configured as analog input channels will
read as cleared (a low level). Pins config-
ured as digital inputs will convert as an
analog input. Analog levels on a digitally
configured input will not affect the
conversion accuracy.
ital input may cause the input buffer to
consume current out of the device’s
specification limits.
PIC18LFXX20
10.67 MHz
21.33 MHz
1.33 MHz
2.67 MHz
5.33 MHz
DS39609B-page 219
OH
666 kHz
—
or V
OL
) will be