Datasheet

PIC16F631/677/685/687/689/690
DS41262E-page 256 © 2008 Microchip Technology Inc.
FIGURE 17-18: A/D CONVERSION TIMING (NORMAL MODE)
TABLE 17-16: A/D CONVERSION REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Operating Temperature -40°C ≤ T
A ≤ +125°C
Param
No.
Sym. Characteristic Min. Typ† Max. Units Conditions
130* T
AD A/D Clock Period 1.5 — — μsTOSC-based, VREF ≥ 2.5V
3.0* — — μsT
OSC-based, VREF full range
A/D Internal RC
Oscillator Period 3.0* 6.0 9.0* μs
ADCS<1:0> = 11 (RC mode)
At V
DD = 2.5V
2.0* 4.0 6.0* μsAt V
DD = 5.0V
131 TCNV Conversion Time
(not including
Acquisition Time)
(1)
—11—TAD Set GO bit to new data in A/D Result
register
132* TACQ Acquisition Time
(2)
5*
11.5
—
—
—
μs
μs The minimum time is the amplifier
settling time. This may be used if the
“new” input voltage has not changed
by more than 1 LSb (i.e., 4.1 mV @
4.096V) from the last sampled
voltage (as stored on C
HOLD).
134 T
GO Q4 to A/D Clock
Start
—TOSC/2 — — 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.
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: ADRESH and ADRESL registers may be read on the following T
CY cycle.
2: See Table 9-1 for minimum conditions.
131
130
132
BSF ADCON0, GO
Q4
A/D CLK
A/D Data
ADRES
ADIF
GO
Sample
OLD_DATA
Sampling Stopped
DONE
NEW_DATA
987 3210
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.
1 TCY
6
134 (TOSC/2)
(1)
1 TCY