PIC17C7XX Datasheet, PDF (180/328 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM Microcontrollers with 10-bit A/D

PIC17C7XX
Figure 16-4 shows the conversion sequence, and the
terms that are used. Acquisition time is the time that the
A/D module’s holding capacitor is connected to the
external voltage level. Then there is the conversion time
of 12 TAD, which is started when the GO bit is set. The
sum of these two times is the sampling time. There is a
minimum acquisition time to ensure that the holding
capacitor is charged to a level that will give the desired
accuracy for the A/D conversion.
FIGURE 16-4: A/D CONVERSION SEQUENCE
A/D Sample Time
Acquisition Time A/D Conversion Time
A/D conversion complete, result is loaded in ADRES register.
Holding capacitor begins acquiring voltage level on selected
channel ADIF bit is set
When A/D conversion is started
(setting the GO bit)
When A/D holding capacitor starts to charge.
After A/D conversion, or when new A/D channel is selected
DS30289A-page 180
© 1998 Microchip Technology Inc.