The A5989 includes fixed off-time pulse width modulation (PWM) current regulators, along with 2- bit nonlinear DACs (digital-to-analogue converters) that allow stepper motors to be controlled in full, half, and quarter step modes.
According to Allegro the device is being targeted at the consumer, industrial and office automation markets with end applications that include point of sale, lottery, ticketing, laser, inkjet and label printers, copiers, vending, and ATM machines.
The A5989 PWM current regulator uses the company’s patented mixed-decay mode for reduced audible motor noise, increased step accuracy, and reduced power dissipation and the DC driver can operate in forward, reverse, coast and brake modes with either fast or slow PWM decay control.
Protection features include thermal shutdown with hysteresis, under voltage lockout , crossover current, and over current protection. Low current sleep mode is included to improve efficiency.
The A5989 is supplied in a leadless 6 mm × 6 mm × 0.9 mm, 36-pin QFN package with exposed power tab for enhanced thermal performance. The package is lead (Pb) free, with 100% matt-tin leadframe plating.
