General pinout of all TMC2xxx SilentStepSticks v1.x:
General pinout of all TMC2xxx SilentStepSticks v2.x and all TMC516x SilentStepSticks:
The motor supply voltage VM is a strong power supply with a high voltage. Always ensure that there cannot occur voltage spikes on power up. Further Information: Pololu - Understanding Destructive LC Voltage Spikes.
A 100uF capacitor (low ESR) near every SilentStepStick driver is recommended for best performance and for supply voltages >=24V a suppressor diode (TVS diode) for over-voltage protection.
Only after the logic supply voltage VIO is present and stable, the driver inputs (STEP, DIR, EN, CFG…) can be driven with a high level.
If the motor is running/moving, then it is not allowed to switch off the power supply. Always make sure that the motor stands still and the motor outputs are deativated on shutting down, otherwise the driver IC can get damaged (because of back EMF). An emergency stop can be realized, when the EN pin is set to VIO (high). This will switch off all motor output drivers and will put the motor into freewheeling.
At power-up the motor supply voltage VM should come up first and then the logic supply voltage VIO. On power-down the logic supply voltage VIO should turned off at first and then the motor supply voltage VM, because the internal logic of the TMC2xxx driver is powered from VM. To ensure the correct powering a schottky diode from VIO (anode) to VM (cathode) can be added. The v2 Protectors for SilentStepSticks include this schottky diode.
There is no special power-up or power-down sequence needed. If the SilentStepStick is only powered with 5V (logic) then a current can flow backwards to VM. In this case it is not allowed to enable the driver (motor outputs) and no loads (e.g. fans) should be on VM (<=4V), because the current will be drawn from the logic supply VIO.