LSI/CSI LS8397

The LS8397 stepper motor controller generates four phase drive signal outputs for controlling two-phase bipolar and four-phase unipolar motors. These outputs drive two H-bridges for the two motor windings in a bipolar motor, or four drive transistors for two center-tapped windings in a unipolar motor. The motor can operate in full-step mode with normal drive (two-phase-on) or wave drive (one-phase-on), as well as half-step mode. The LS8397 provides two inhibit outputs for controlling the drive stage of each motor phase. The circuit uses STEP, FRD/REV, and HALF/FULL inputs to generate control signals for the output stage in the translator. A dual PWM chopper circuit uses an on-chip oscillator, latches, and voltage comparators to regulate current in the motor windings. A separate reference voltage VREFh input is also provided to reduce holding torque when the motor is not rotating. In the half-step sequence, phase drive alternates between one-phase-on and two-phase-on in consecutive steps at full power, producing significant ripple in the output torque. An input CT_EN is provided to select an operating mode that corrects torque ripple. The CONTROL input determines whether the chopper acts on the phase drive outputs or the inhibit outputs.

• Controls bipolar and unipolar motors
• Operates as L297 with added features: optional torque ripple compensation phase drive; optional auto-switching between step and hold torque
• Supply current < 400μA
• Half-step and full-step modes
• Normal/wave drive
• Direction control
• Reset input
• Step control input
• Enable input
• PWM chopper circuit for current control
• Two overcurrent sense comparators with external reference inputs
• All inputs and outputs TTL/CMOS compatible (TTL at 5V operation)
• 4.75V to 7V operating voltage (VDD - Vss)
• Package types: LS8397 (DIP), LS8397-S (SOIC), LS8397-TS (TSSOP)

• Not mentioned