Circuit for 4 bit Digital to Analog Converter (DAC) in current mode. The open lines act as bit inputs. Grounding the terminals represent bit 0 and connecting the terminals to the inverting terminal of op-amp (- terminal) represent bit 1. The output of the op-amp gives the analog equivalent of the digital bits fed into the open lines. Remember, you must to connect the open lines to ground for bit 0 and for bit 1 you need to connect the open lines to the op- amp negative. If any lines are left open it will not work as a DAC.
