PIC16LF18854 Datasheet, PDF (340/668 Pages) Microchip Technology – C Compiler Optimized RISC Architecture

PIC16(L)F18856/76
TABLE 23-1: ADC CLOCK PERIOD (TAD) VS. DEVICE OPERATING FREQUENCIES
ADC Clock Period (TAD)
Device Frequency (FOSC)
ADC
Clock Source
ADCCS<5:0>
32 MHz
20 MHz
16 MHz
8 MHz
4 MHz
1 MHz
FOSC/2
FOSC/4
FOSC/6
FOSC/8
000001
000010
000011
000100
62.5ns⁽²⁾
125 ns⁽²⁾
187.5 ns⁽²⁾
250 s⁽²⁾
100 ns⁽²⁾
200 ns⁽²⁾
300 ns⁽²⁾
400 ns⁽²⁾
125 ns⁽²⁾
250 ns⁽²⁾
375 ns⁽²⁾
500 s⁽²⁾
250 ns⁽²⁾
500 ns⁽²⁾
750 ns⁽²⁾
1.0 s
500 ns⁽²⁾
1.0 s
1.5 s
2.0 s
2.0 s
4.0 s
6.0 s
8.0 s⁽³⁾
...
FOSC/16
...
FOSC/128
FRC
Legend:
Note 1:
2:
3:
4:
...
...
...
...
...
...
...
000101
500 ns⁽²⁾
800 ns⁽²⁾
1.0 s
2.0 s
4.0 s
16.0 s⁽²⁾
...
...
...
...
...
...
...
111111
ADCS(ADCON0
<4>)=1
4.0 s
1.0-6.0 s⁽¹⁾
6.4 s
1.0-6.0 s⁽¹⁾
8.0 s
1.0-6.0 s⁽¹⁾
16.0 s⁽³⁾
1.0-6.0 s⁽¹⁾
32.0 s⁽²⁾
1.0-6.0 s⁽¹⁾
128.0 s⁽²⁾
1.0-6.0 s⁽¹⁾
Shaded cells are outside of recommended range.
See TAD parameter for FRC source typical TAD value.
These values violate the required TAD time.
Outside the recommended TAD time.
The ADC clock period (TAD) and total ADC conversion time can be minimized when the ADC clock is derived from the
system clock FOSC. However, the FRC oscillator source must be used when conversions are to be performed with the
device in Sleep mode.
FIGURE 23-2:
ANALOG-TO-DIGITAL CONVERSION TAD CYCLES
Precharge
Time
1-127 TINST
(TPRE)
Acquisition/
Sharing Time
1-127 TINST
(TACQ)
Conversion Time
(Traditional Timing of ADC Conversion)
TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11
b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
External and Internal External and Internal
Channels are
Channels share
Conversion starts
charged/discharged charge
Holding capacitor CHOLD is disconnected from analog input (typically 100 ns)
If ADPRE  0
If ADACQ 0
Set GO/DONE bit
If ADPRE = 0
If ADACQ = 0
(Traditional Operation Start)
On the following cycle:
AADRES0H:AADRES0L is loaded,
ADIF bit is set,
GO/DONE bit is cleared
DS40001824A-page 340
Preliminary
 2016 Microchip Technology Inc.