
2003 Microchip Technology Inc.
DS39582B-page 195
PIC16F87XA
FIGURE 17-19:
A/D CONVERSION TIMING
TABLE 17-15: A/D CONVERSION REQUIREMENTS
131
130
132
BSF ADCON0, GO
Q4
A/D CLK
A/D DATA
ADRES
ADIF
GO
SAMPLE
OLD_DATA
Sampling Stopped
DONE
NEW_DATA
(TOSC/2)(1)
98
7
2
1
0
Note: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP
instruction to be executed.
1 TCY
. . .
Param
No.
Symbol
Characteristic
Min
Typ
Max
Units
Conditions
130
TAD
A/D Clock Period
PIC16F87XA
1.6
—
sTOSC based, VREF ≥ 3.0V
PIC16LF87XA
3.0
—
sTOSC based, VREF ≥ 2.0V
PIC16F87XA
2.0
4.0
6.0
s
A/D RC mode
PIC16LF87XA
3.0
6.0
9.0
s
A/D RC mode
131
TCNV
Conversion Time (not including S/H time)
(Note 1)
—12
TAD
132
TACQ
Acquisition Time
(Note 2)
10*
40
—
s
The minimum time is the
amplifier settling time. This may
be used if the “new” input volt-
age has not changed by more
than 1 LSb (i.e., 20.0 mV @
5.12V) from the last sampled
voltage (as stated on CHOLD).
134
TGO
Q4 to A/D Clock Start
—
TOSC/2 §
—
If the A/D clock source is
selected as RC, a time of TCY is
added before the A/D clock
starts. This allows the SLEEP
instruction to be executed.
*
These parameters are characterized but not tested.
Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
§
This specification ensured by design.
Note
1:
ADRES register may be read on the following TCY cycle.
2: