Motor driver ICs Stepping motor driver BA6846FS / BA6846FV The BA6846FS and BA6846FV are stepping motor drivers with a maximum output current of 0.5A. The logic input allows three output modes : forward, reverse, and power save. The ICs have low output saturation voltage and are capable of driving motors at low supply voltage. Applications Stepping motors for floppy disk drives Features 1) Low output saturation voltage. 2) Power save circuit. 3) Thermal shutdown circuit. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 741 Motor driver ICs Block diagram Pin descriptions 742 BA6846FS / BA6846FV Motor driver ICs BA6846FS / BA6846FV Input / output circuits Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 5V, VM1, 2 = 5V) Input / output truth table 743 Motor driver ICs Application example BA6846FS BA6846FV 744 BA6846FS / BA6846FV Motor driver ICs Operation notes (1) Control logic pins Do not apply voltage to control logic pins when the VCC voltage is not applied to the IC. The voltage of each pin should be less than VCC, if applied, and should be more than the ground voltage. (2) PCB arrangement When changing the rotational direction of a motor, a large current of up to a few hundred milliamperes can flow between the motor power supply and the PGND pin. Depending on the application, this large output current may flow back to input pins, resulting in output oscillation or other malfunctions. Make sure that your design does not allow a common impedance between the large current output lines and the input section. Suppress the power supply impedance to low levels, otherwise output oscillation may occur. BA6846FS / BA6846FV (3) Package power dissipation The power dissipated by the IC varies widely with the supply voltage and the output current. Give full consideration to the package power dissipation rating when setting the supply voltage and the output current. (4) Ground pins The GND and SUB pins should have the lowest potential (ground potential) in the IC. (5) Thermal shutdown circuit This circuit shuts down all the driver outputs when the chip junction temperature is increased to about 175C (typical). The thermal shutdown circuit is deactivated when the temperature drops to about 20C (typical). (6) Logic input pins These pins have characteristics negatively correlated to temperature. Give full consideration to the temperature effect when using the IC. Electrical characteristic curves 745 Motor driver ICs External dimensions (Units: mm) 746 BA6846FS / BA6846FV