Techniques for generating digital outputs as stochastic bitstreams with activation function mapping are provided. In one aspect, a system includes: a shared circuitry component including a RNG for generating a sequence of random addresses to read a random sequence of digital voltage references stored in a LUT, and a DAC for converting the random sequence of digital voltage references into random analog voltage references VL; and a comparator(s) for comparing the random analog voltage references VL and input analog voltages VN in sequences of comparisons to produce sequences of digital pulses as stochastic bitstreams. A system having multiple comparators for simultaneously comparing each of the random analog voltage references VL against more than one of the input analog voltages VN in parallel is also provided, as is a method for generating digital outputs from input analog voltages VN.