AMIS-30624 I2C Microstepping Motordriver
Data Sheet
15.3.6. Charge Pump Monitoring
If the charge pump voltage is not sufficient for driving the high side transistors (due to a failure), an internal HardStop command is
issued. This is acknowledged to the master by raising the flag <CPFail> (available with command GetFullStatus1).
In case this failure occurs while a motion is ongoing, the flag <StepLoss> is also raised.
15.3.7. Electrical Defect on Coils, Detection and Confirmation
The principle relies on the detection of a voltage drop on at least one transistor of the H-bridge. Then the decision is taken to open the
transistors of the defective bridge.
This allows the detection of the following short circuits:
• External coil short circuit
• Short between one terminal of the coil and Vbat or Gnd
Open circuits are detected by a 100 percent PWM duty cycle value during a long time.
Table 23: Electrical Defect Detection
Pins
Fault Mode
Short circuit to GND
Short circuit to Vbat
Open
Yi or Xi
Yi or Xi
Yi or Xi
Y1 and Y2
X1 and X2
Xi and Yi
Short circuited
Short circuited
Short circuited
Remark: One cannot detect an internal short in the motor.
AMI Semiconductor – Apr. 2007, Rev 3.1, M-20664-003
35
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