The MAX9867 includes two 16-bit ADCs. The first ADC is used to record left-channel microphone and line-input audio signals. The second ADC can be used to record right-channel microphone and line-input signals, or it can be configured to accurately measure DC voltages. When measuring DC voltages from AUX input, both the left and right ADCs must be enabled by setting ADLEN and ADREN in register 0x17.