Other Parts Discussed in Thread: TCA9517
Tool/software:
Hello,
In my application, I am using this DRV8873H to drive my resistive load, my resistive load is about 4 Ohms.
The load is located about 2m apart from the main control, together with 5 other I2C peripherals.
I am using TI's TCA9517 to be able to extend the I2C cable with 4,7k pull up on both sides.
This is how my application looks like:
Normally, when the Input Signal (at DRV8873H) is OFF, everything works fine. I can talk to the peripherals using the I2C lines.
But when I supply a 20% Duty Cycle, 200Hz PWM signal to heat the resistive load up, the driver interferes with my +3V3 line with these "spikes" at exactly 200Hz => this is interfering with my I2C communication, I cannot perform communication any more.
This is how it looks on the oscilloscope at the I2C CLOCK line when this happens: (it's a bit above GND because of the TCA9517 but that's expected)
This is how the signal looks at the output of DRV8873H:
When I turn the Input Signal OFF, everything works fine again.
How do I get rid of these spikes?