A data channel includes a power constrained first channel portion to receive energy from a limited power source and a non-power constrained second channel portion to receive energy from a different power source than the first channel portion. The first channel portion includes an ADC circuit to output an ADC data sample, a first transmitter circuit configured to serially transmit data that includes ON bits and OFF bits, and logic circuitry configured to derive transmit data from the ADC data sample. The transmitter circuit uses more energy transmitting the ON bits than the OFF bits, and the derived transmit data has a reduced number of the ON bits from the ADC data sample. The second channel portion includes a first receiver circuit to receive the derived transmit data from the first transmitter circuit of the first channel portion.