PIC16F872_06 Datasheet, PDF (139/168 Pages) Microchip Technology – 28-Pin, 8-Bit CMOS Flash Microcontroller with 10-Bit A/D

PIC16F872
FIGURE 14-16: A/D CONVERSION TIMING
BSF ADCON0, GO
Q4
A/D CLK ¹³²
A/D DATA
ADRES
ADIF
GO
(TOSC/2)⁽¹⁾
1 TCY
131
130
9
8
7 ^{... ...}
2
1
0
OLD_DATA
NEW_DATA
DONE
SAMPLE
SAMPLING STOPPED
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.
TABLE 14-10: A/D CONVERSION REQUIREMENTS
Param
No.
Sym
Characteristic
130 TAD A/D Clock Period
Standard(F)
Extended(LF)
Standard(F)
Extended(LF)
131 TCNV Conversion Time (not including S/H time)
(Note 1)
132 TACQ Acquisition Time
Min
1.6
3.0
2.0
3.0
(Note 2)
Typ†
—
—
4.0
6.0
—
40
Max Units
Conditions
—
μs TOSC based, VREF ≥ 3.0V
—
μs TOSC based, VREF ≥ 2.0V
6.0
μs A/D RC mode
9.0
μs A/D RC mode
12
TAD
—
μs
10*
—
—
μs 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.
Note
* 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.
1: ADRES register may be read on the following TCY cycle.
2: See Section 10.1 for min. conditions.
© 2006 Microchip Technology Inc.
DS30221C-page 137