Datasheet

PIC18F66K80 FAMILY
DS39977F-page 580  2010-2012 Microchip Technology Inc.
FIGURE 31-21: A/D CONVERSION TIMING
TABLE 31-26: A/D CONVERSION REQUIREMENTS
Param
No.
Symbol Characteristic Min Max Units Conditions
130 TAD A/D Clock Period 0.8 12.5
(1)
sTOSC based, VREF  3.0V
1.4 25
(1)
sVDD = 3.0V; TOSC based,
V
REF full range
—1
s A/D RC mode
—3
sVDD = 3.0V; A/D RC mode
131 T
CNV Conversion Time
(not including acquisition time)
(2)
14 15 TAD
132 TACQ Acquisition Time
(3)
1.4 — s -40°C to +125°C
135 T
SWC Switching Time from Convert  Sample — (Note 4)
TBD TDIS Discharge Time 0.2 — s -40°C to +125°C
Note 1: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
2: ADRES registers may be read on the following TCY cycle.
3: The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale
after the conversion (V
DD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50.
4: On the following cycle of the device clock.
131
130
132
BSF ADCON0, GO
Q4
A/D CLK
A/D DATA
ADRES
ADIF
GO
SAMPLE
OLD_DATA
SAMPLING STOPPED
DONE
NEW_DATA
(Note 2)
11 10 9 2 1 0
Note 1: If the A/D clock source is selected as RC, a time of T
CY is added before the A/D clock starts. This allows the SLEEP instruction to
be executed.
2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input.
. . .
. . .
TCY (Note 1)