Microcontroller Interfacing with Stepper Motor - Current Consumption

[FreshmanNewbie]

I have this MPC5606S Microcontroller which I have interfaced with this Sonceboz Bi polar Stepper Motor. The Microcontroller is powered up by 5V and 3.3V and the Stepper motor interface is connected to the 5V Power domain.

I am a little new to this stepper motor working.

This is the connection between the Microcontroller and the stepper motor :




There is also another same stepper motor for the "SPEED" net but I am showing only for the Tacho net.

The input to the COS+, COS- pins of the Stepper are 15kHz, 50% duty cycle PWM Input and the rise time & fall time of the signals is in the order of 30ns-40ns

All I want to understand is the how to calculate - how much current does the motor consume during the normal condition? How to calculate the current consumption of this bipolar stepper motor which takes the current from the Microcontroller pins? I am trying to calculate the maximum output current of the Microcontroller through its output ports.

 

[stenzer]

Hi,

according to the MPC5606S datasheet the SMD (Stepper Motor Driver) pins provide additional current capability to drive stepper motor loads. I had a short look on the datasheet, and I was not able to find an actual current rating (I have no experince with MCUs from NXP). Nevertheless, the current ratings stated in the motor's datasheet are pretty high, and I doubt the MCU can provide such high currents even for the lowest stated motor current. The MCU will not withstand the "short" presented by the motor. You need a dedicated stepper motor driver board/IC.

BR

 

[KlausST]

Hi,

Usually when the datasheet gives not full description, then there will be additional documents.

An NXP search shows 32 MPC5606 related documents. Besides the datasheet there are
* application notes
* reference manuals
* user guides
* quick start guides
* ... others

Search | NXP Semiconductors

They are for free and reliable..
It took much effort for the manufacturer to create them ... especially for you ... so use them ;-)

Klaus

Besides this you need to understand stepper motor operation.
* to make a stepper move you need to ramp up the (fundamental) motor coil frequency and the phase needs to be 90° shifted from coil to coil.
* motor coil current and U-I phase shift depends on a lot of things ... like RPM and torque.