PBL3774-1

February 1999 PBL 3774/1 Dual Stepper Motor Driver Description The PBL 3774/1 is a switch-mode (chopper), constant-current driver IC with two channels, one for each winding of a two-phase stepper motor. The circuit is similar to Ericsson´s PBL 3771/1 and PBL 3772/1. While all Dual stepper motor drivers are optimized for microstepping applications, the PBL 3774/1 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 (Digital-to-Analog Converter) PBM 3960/1. A complete driver system consists of these two ICs, a few passive components and a microprocessor for generation of the proper control and data codes required for microstepping. In full/halfstepping applications, Ericsson Component’s PBD 3517/1 can be used as a phase generator (translator) to derive the necessary signals for the PBL 3774/1. The PBL 3774/1 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. The close match between the two driver channels guarantees consistent output current ratios and motor positioning accuracy. Key Features Dual chopper driver in a single package. Operation at -40 °C. 1000 mA continuous output current per channel. Low power dissipation, 2.6 W at 2 x 750 mA ou...