SLVSBH2C June 2012 – December 2015 DRV8823-Q1
PRODUCTION DATA.
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The DRV8823-Q1 can be used to drive two bipolar stepper motors.
Table 5 lists the design requirements for this design example.
DESIGN PARAMETER | REFERENCE | EXAMPLE VALUE |
---|---|---|
Supply voltage | VM | 24 V |
Motor winding resistance | RL | 7.4 Ω/phase |
Motor full-step angle | θstep | 1.8°/step |
Target microstepping angle | nM | 1/8 step |
Target motor speed | V | 120 rpm |
Target full-scale current | IFS | 1 A |
The appropriate motor voltage will depend on the ratings of the motor selected and the desired torque. A higher voltage shortens the current rise time in the coils of the stepper motor allowing a greater average torque. Using a higher voltage also allows the motor to operate at a faster speed than a lower voltage.
The current path running to the motor starts from the supply VM, then goes through the high-side sourcing NMOS power FET, moves through the inductive winding load of the motor, then through the low-side sinking NMOS power FET, and finally going through the external sense resistor. Power dissipation losses in both NMOS power FETs inside of the DRV8823-Q1 are shown in the following equation.
The DRV8823-Q1 has been measured to be capable of 1.5-A continuous current with the HTSSOP package at 25°C on standard FR-4 PCBs. The max continuous current will vary based on PCB design and the ambient temperature.