TMC2100 DATASHEET (Rev. 1.07 / 2017-MAY-15)
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10 Driver Diagnostic and Protection
The TMC2100 drivers supply a set of diagnostic and protection capabilities, like short to GND
protection and overtemperature detection and protection.
10.1 Temperature Measurement
The TMC2100 driver integrates a temperature sensor for protection against excess heat. In case the
temperature reaches 150°C the TMC2100 reacts with automatic switching off. If the chip cools down
afterwards and its temperature reaches 120°C, it recovers automatically and starts working.
Heat is mainly generated by the motor driver stages and the on-chip voltage regulator. The central
temperature detector can detect heat accumulation on the chip, i.e. due to missing convection cooling
or rising environment temperature. If continuous operation in hot environments is necessary, a more
precise processor based temperature measurement should be used to realize application specific
overtemperature detection. The thermal shutdown is just an emergency measure and temperature
rising to the shutdown level should be prevented by design.
Attention
Overtemperature protection cannot in all cases avoid thermal destruction of the IC. In case the rated
motor current is exceed, excess heat generation can quickly heat up the driver before the
overtemperature sensor can react. This is due to a delay in heat conduction over the IC die.
After triggering the overtemperature sensor, the driver remains switched off until the system
temperature falls below 120°C to avoid continuous heating to the shutdown level.
10.2 Short to GND Protection
The TMC2100 power stages are protected against a short circuit condition by an additional measure-
ment of the current flowing through the high-side MOSFETs. This is important, as most short circuit
conditions result from a motor cable insulation defect, e.g. when touching the conducting parts
connected to the system ground. The short detection is protected against spurious triggering, e.g. by
ESD discharges, by retrying three times before switching off the motor.
Once a short condition is safely detected, the corresponding driver bridge (A or B) becomes switched
off and the error becomes indicated at the diagnostic ERROR output. In order to restart the motor,
disable and re-enable the driver. Note, that short protection cannot protect the system and the power
stages for all possible short events, as a short event is rather undefined and a complex network of
external components may be involved. Therefore, short circuits should basically be avoided.
10.3 Emergency Stop
The driver provides a negative active enable pin ENN to safely switch off all power MOSFETs. This
allows putting the motor into freewheeling. Further, it is a safe hardware function whenever an
emergency stop not coupled to software is required.
10.4 Diagnostic Output
The driver provides a negative active enable pin ENN to safely switch off all power MOSFETs. This
allows putting the motor into freewheeling. Further, it is a safe hardware function whenever an
emergency stop not coupled to software is required.
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