32.1.2 Channel Selection
The ADPCH32.7.8 ADPCH register determines which channel is connected to the Sample-and-Hold circuit.
There are several channel selections available as shown in the following selection table:
ADPCH | ADC Positive Channel Input |
---|---|
111111 |
Fixed Voltage Reference (FVR)(2) |
111110 |
DAC1 output(1) |
111101 |
Temperature Indicator(3) |
111100 |
AVSS (Analog Ground) |
100011 to
111000 |
Reserved. No channel connected. |
110111 |
RG7/ANG7 |
110110 |
RG6/ANG6 |
110101 |
RG5/ANG5 |
110100 |
RG4/ANG4 |
110011 |
RG3/ANG3 |
110010 |
RG2/ANG2 |
110001 |
RG1/ANG1 |
110000 |
RG0/ANG0 |
101111 |
Reserved. No channel connected |
101110 |
RF6/ANF6 |
101101 |
RF5/ANF5 |
101100 |
RF4/ANF4 |
101011 |
Reserved. No channel connected |
101010 |
RF2/ANF2 |
101001 |
RF1/ANF1 |
101000 |
Reserved. No channel connected |
100111 |
RE7/ANE7 |
100110 |
RE6/ANE6 |
100101 |
RE5/ANE5 |
100100 |
RE4/ANE4 |
100011 |
RE3/ANE3 |
100010 |
RE2/ANE2 |
100001 |
RE1/ANE1 |
100000 |
RE0/ANE0 |
011111 |
RD7/AND7 |
011110 |
RD6/AND6 |
011101 |
RD5/AND5 |
011100 |
RD4/AND4 |
011011 |
RD3/AND3 |
011010 |
RD2/AND2 |
011001 |
RD1/AND1 |
011000 |
RD0/AND0 |
010111 to
010000 |
Reserved. No channel connected |
001111 |
RB7/ANB7 |
001110 |
RB6/ANB6 |
001101 |
RB5/ANB5 |
001100 |
RB4/ ANB4 |
001011 |
RB3/ANB3 |
001010 |
RB2/ ANB2 |
001001 |
RB1/ ANB1 |
001000 |
RB0/ANB0 |
000111 |
RA7/ANA7 |
000110 |
RA6/ANA6 |
000101 |
RA5/ANA5 |
000100 |
RA4/ ANA4 |
000011 |
RA3/ ANA3 |
000010 |
RA2/ ANA2 |
000001 |
RA1/ ANA1 |
000000 |
RA0/ANA0 |
When changing channels, a delay is required before starting the next conversion.
Refer to the “ADC Operation” section for more information.
Important: It is recommended to discharge the
Sample-and-Hold capacitor when switching between ADC channels by starting a conversion on a
channel connected to VSS and terminating the conversion after the acquisition
time has elapsed. If the ADC does not have a dedicated VSS input channel, the
VSS selection (DAC1R[4:0] = b'00000') through the DAC output channel can be
used. If the DAC is in use, a free input channel can be connected to VSS, and
can be used in place of the DAC.