DRV8818 Datasheet, PDF (12/20 Pages) Texas Instruments – STEPPER MOTOR CONTROLLER IC

DRV8818
SLVSAX9A – SEPTEMBER 2011 – REVISED FEBRUARY 2012
Protection Circuits
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Overcurrent Protection (OCP)
If the current through any FET exceeds the preset overcurrent threshold, all FETs in the H-bridge will be disabled
for a period of approximately 800 µs, or until the ENABLEn pin has been brought inactive high and then back
low, or power is removed and re-applied. Overcurrent conditions are sensed in both directions; i.e., a short to
ground, supply, or across the motor winding will all result in an overcurrent shutdown.
Note that overcurrent protection does not use the current sense circuitry used for PWM current control and is
independent of the Isense resistor value or VREF voltage.
Thermal Shutdown (TSD)
If the die temperature exceeds safe limits, all drivers in the device are shut down and the indexer is reset to the
home state. Once the die temperature has fallen to a safe level operation resumes.
Undervoltage Lockout (UVLO)
If at any time the voltage on the VM or VCC pins falls below the VM or VCC undervoltage lockout threshold
voltage, all circuitry in the device will be disabled, and the indexer will be reset to the home state. Operation will
resume when VM and VCC both rise above their UVLO thresholds.
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