La description

Feature ●± 2.5 Ma rate of *5 V output ●Low rDS (ON) output (typically 0.*5 EU source, 0.*6 Euro sink) ●Since the drive current decay mode detection / selection ●3.0 to 5.5 V logic supply voltage range ●Mixed fast and slow current - decay mode ●Auto-oriented output ●Synchronous rectification for low power dissipation ●Internal under voltage lockout (UVLO) and thermal shutdown circuit ●Cross-current protection Description A***7SED and A***7SLP are two complete micro stepping motor driver with built-in converter. Both in whole, 1 / 2, 1 / 4 and 1 / 8 step modes operate bipolar stepper motors, the output drive capability of *5 V and ± 2.5 amps. A***7 includes a fixed off-time current regulator; the regulator is in low, fast or mixed decay modes. This current decay control scheme results in reduced audible motor noise, increased step accuracy and reduced power dissipation. Converter is the key to the easy implementation of A***7. Simple in the "step" , enter a pulse, the motor will have step (full, 1 / 2, 1 / 4 or 1 / 8 step, according to the two logic s of the case may be). There are no phase sequence tables, high frequency control lines or complex interfaces. A***7 interface is ideal for complex μP is unavailable or is overburdened. Internal synchronous rectification control circuitry is used to improve the pulse-width modulation (PWM) operation of the power consumption. Internal circuit protection includes thermal shutdown with hysteresis, under voltage lockout (UVLO) and crossover current protection. No special power-up sequencing. A***7 has two power packages to choose from, with a copper batwing that **-pin plastic PLCC chip, and with an exposed thermal pad (suffix LP) of thin (<1.2 mm) **-pin TSSOP. The SLP package is lead-free products, and the lead frame with **0% matte tin plating.