Anaheim MDM40001 warranty Timing, Fault Protection, Over Temperature Protection

TIMING

The Direction and Microstep Resolution Select inputs are synchronized with the positive going edge of the Step Clock input. When the Step Clock input goes high, the Direction and Microstep Select inputs are latched and further changes to the inputs are ignored until the next rising edge of the Step Clock input.

After these signals are latched, the MDM40001 looks to see if any changes have occurred to the Direction and the Microstep Select inputs. If a change has occurred, the MDM40001 will execute the change before taking the next step. Only AFTER the change has been executed will the step be taken. If no change has occurred the MDM40001 will simply take the next step. This feature works as an automatic debounce for the Direction and Microstep Select inputs.

The minimum pulse width for the Clock input is 75 nS. The typical execution time for a Direction or Microstep Select change is 100nS. The typical execution time for a Clock input is 100nS.

The Reset and Enable inputs are asynchronous to any input and can be changed at any time.

The Reset requires a minimum pulse width of 500 nS.

The Fullstep output typically occurs 75nS after the positive edge of the Step Clock (excluding changes to the Direction or the Microstep Select inputs).

FAULT PROTECTION

The MDM40001 is internally protected against over temperature and short circuits. The over temperature set point is between 60EC and 70EC. Care should be taken when choosing a heatsink so that there is good thermal flow, otherwise hot spots may occur in the MDM40001 which will reduce the effectiveness of the thermal protection.

The short circuit protection consists of PHASE to PHASE, PHASE to GROUND, and +V to PHASE.

If any fault is detected by the MDM40001, the outputs will be disabled and can not be re- enabled without resetting or powering down the driver. At the same time the open collector FAULT output is turned on.

The FAULT output is non-isolated and has the ability to sustain the maximum driver voltage. It is capable of sinking up to 25mA which can be used to drive a small relay or LED.

OVER TEMPERATURE PROTECTION

The MDM40001 microstepping is a power device and is designed to protect itself from overheating. It does this by monitoring the surface temperature of the drive plate and will automatically shutdown if the temperature reaches 60°C (152°F).

To prevent nuisance shutdowns, proper heatsinking is required to limit the temperature at the drive plate.

A thermal grease or thermal pad should be used between the drive plate and the mounting surface of the heatsink. The fins of the heatsink should be mounted vertically with at least 3" of space below and above the heatsink for efficient cooling.

In some applications fan cooling will be required to maintain the plate temperature below the 60°C shutdown temperature.

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