SLA7051M Datasheet | Allegro MicroSystems

or r t o ive M r D UNIPOLAR STEPPER-MOTOR TRANSLATOR/PWM DRIVER bining low-power CMOS logic with high-current, high-voltage power FET outputs, the SLA7051M translator/driver provides plete control and drive for a two-phase unipolar stepper motor with internal fixed off time, pulse-width modulation (PWM) control of the output current in a power multi-chip module (PMCM™). The CMOS logic section provides the sequencing logic, direction, full/half-step control, synchronous/asynchronous PWM operation, and a “sleep” function. The minimum CLOCK input is an ideal fit for applications where a plex µP is unavailable or overburdened. TTL or LSTTL may require the use of appropriate pull-up resistors to ensure a proper input-logic high. For PWM current control, the maximum output current is determined by the user’s selection of a reference voltage and sensing resistor. The NMOS outputs are capable of sinking up to 2 A and withstanding 46 V in the off state. Ground-clamp and flyback diodes provide protection against inductive transients. Special Data Sheet 28210C- power-up sequencing is not required. Full-step (2 phase) and half-step operation are externally selectable. Two-phase drive energizes two adjacent phases in each detent position (AB-BC-CD-DA). This sequence mode offers an improved torquespeed product, greater detent torque, and is less susceptable to motor resonance. Half-step excitation alternates between the one-phase and two-phase modes (A-AB-B-BC-C-CD D-DA), providing an eight-step sequence. The SLA7051M is supplied in an 18-pin single in-line power-tab package with leads formed for vertical mounting (suffix LF871) or horizontal mounting (suffix LF872). The tab is at ground potential and needs no insulation. For high-current or high-frequency applications, external heat sinking may be required. This device is rated for continuous operation between -20°C and...