Hi,
Looking at the features of intelligent stepper motor driver (L6470), I have decided to use it for an application where I will be having 16 stepper motor drivers
which will be controlled by single STM32 MCU. I am done with board design and to start with, we have purchased evaluation boards of L6470 and STM32 MCU.
Both boards are integrated for controlling two stepper motors.
While I run the stepper motor, I see that, motor runs for @30 seconds and then stops because L6470 is getting heated.
I have done below homework before raising this query on this forum.
1. Studied AN4144 and done tunning of L6470 parameters for the motor we are using. These parameters are feed to L6470 through SPI bus from STM32 MCU.
2. Calculated parameters like KVAL, ST_SLP, INT_SPEED, FN_SLP etc.
3. We used SPINFamily Evaluation Tool 3.2 to calculate above parameters.
Below are motor parameters.
Motor phase resistance: 1.2 Ohm
Motor phase inductance: 4.2 mH
Step angle: 1.8 degrees
L6470 Step Mode: 1/8
Max_SPEED: 3500
Supply voltage: 36V
I have done multiple experiments with different tunning parameters but failed to stop L6470 heating.
Here are some parameters which I calculated fromt the tool I used for the motor we are using.
Ke = 0.13161
Running Target current = 2.5 Amp @Max speed 3500
KVAL_HOLD: 0
KVAL_ACC: 0x1E
KVAL_DEC: 0x1E
KVAL_RUN: 0x1E
ST_SLP: 0x3C
INT_SPEED: 0x0BEC
FN_SLP_ACC: 0x66
FN_SLP_DEC: 0x66
Can you verify, whether these correct for the motor I mentioned above?
Do revert for urgent help to control heating of L6470.
Best regards
Narendra
