The NJM3774 is a switch-mode (chopper), constantcurrent driver with two channels: one for each winding of a two-phase stepper motor. The NJM3774 is equipped with a TTL level compatible Disable input to simplify half-stepping operation. The circuit is well suited for microstepping applications together with the matching dual DAC NJU39610. In full/half stepping applications, the NJM3517 can be used as a phase generator (translator) to derive the necessary signals for the NJM3774. The NJM3774 contains a clock oscillator, which is common for both driver channels, a set of comparators and flip-flops implementing the switching control, and two output H-bridges. Voltage supply requirements are +5 V for logic and +10 to +45 V for the motor. Maximum output current is 1000mA per channel.