NJM3773D2

DUAL STEPPER MOTOR DRIVER NJM3773 s GENERAL DESCRIPTION The NJM3773 is a switch-mode (chopper), constant-current driver with two channels: one for each winding of a two-phase stepper motor. The NJM3773 is also equipped with a Disable input to simplify half-stepping operation. The circuit is well suited for microstepping applications together with an external micro controller. The current control inputs are low current, high impedance inputs, which allows the use of unbuffered DAC or external high resistive resistor divider network. The NJM3773 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, including recirculation diodes. Voltage supply requirements are +5 V for logic and +10 to +45 V for the motor. Maximum output current is 750mA per channel. s PACKAGE OUTLINE NJM3773D2 NJM3773E3 NJM3773FM2 s FEATURES Dual chopper driver 750 mA continuous output current per channel High impedance current control inputs Digital filter on chip eliminates external filtering components Packages DIP22 / PLCC28 / EMP24(Batwing) s BLOCK DIAGRAM Phase 1 Dis1 VR1 C1 NJM3773 VCC V CC – + E1 RQ S Logic + – RC Logic + SQ R – M A1 M B1 VMM1 VMM2 M B2 M A2 Figure 1. Block diagram Phase 2 Dis 2 VR2 C2 GND E2 s PIN CONFIGURATIONS NJM3773 NC 1 MB1 2 E1 3 MA1 4 VMM1 5 GND 6 GND 7 VR1 8 C1 9 Phase1 10 Dis1 11 RC 12 NJM 3773E3 24 NC 23 MB2 22 E2 21 MA2...