An ADC (A/D or A-to-D) is a hardware component that converts analog voltages into digital values that can be recorded in temporal synchronization with 3D measurements, typically enabling force and moment information, together with other biomechanics data such as electromyography and acceleration, to be stored in a C3D file as analog data samples.

The analog data samples generated by an ADC will normally have a fixed digital resolution (typically 12, 14, or 16-bits) and are generated repetitively at a sample rate that defines the bandwidth of the sampled data.  The analog ADC data environment is defined by the ANALOG:SCALE, OFFSET, and GEN_SCALE parameters in each C3D file containing analog data.