Channel Selection

The 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:

Table 1. ADC Positive Input Channel Selections
ADPCH ADC Positive Channel Input
111111 Fixed Voltage Reference (FVR)(2)
111110 DAC1 output(1)
111101 Temperature Indicator(3)
111100 AVSS (Analog Ground)
100011-111011 Reserved. No channel connected.
100010 RE2/ANE2(1)
100001 RE1/ANE1(1)
100000 RE0/ANE0(1)
011111 RD7/AND7(1)
011110 RD6/AND6(1)
011101 RD5/AND5(1)
011100 RD4/AND4(1)
011011 RD3/AND3(1)
011010 RD2/AND2(1)
011001 RD1/AND1(1)
011000 RD0/AND0(1)
010111 RC7/ANC7
010110 RC6/ANC6
010101 RC5/ ANC5
010100 RC4/ ANC4
010011 RC3/ANC3
010010 RC2/ANC2
010001 RC1/ ANC1
010000 RC0/ANC0
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
  1. 1.40/44-pin devices only.

When changing channels, a delay is required before starting the next conversion.

Refer to Section “ADC Operation” for more information.

Important: It is recommended that when switching from an ADC channel of a higher voltage to a channel of a lower voltage, the software selects the Vss channel before switching. 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.