Datasheet

PIC18(L)F1XK22
DS41365E-page 354  2009-2011 Microchip Technology Inc.
FIGURE 25-14: A/D CONVERSION TIMING
TABLE 25-9: A/D CONVERSION REQUIREMENTS
Param
No.
Symbol Characteristic Min. Max. Units Conditions
130* T
AD A/D Clock Period 0.7 25.0
(1)
sTOSC based, VREF  3.0V,
-40°C to +85°C
0.7 4.0
(1)
s
TOSC based, VREF  3.0V,
-40°C to +125°C
1.0 4.0 s
A/D RC mode
131 T
CNV Conversion Time
(not including acquisition time)
(2)
12 12 TAD
132* TACQ Acquisition Time
(3)
1.4 5.0 sVDD 3.0V, RS = 50
135 TSWC Switching Time from Convert - Sample
——
(4)
—
136 TDIS Discharge Time 2 2 s
* These parameters are characterized but not tested.
Note 1: The time of the A/D clock period is dependent on the device frequency and the T
AD clock divider.
2: ADRES register may be read on the following T
CY 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)
987 21 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