Adafruit 12b PWM controler PCA9685 - use with 8.5V high voltage servo

Hello all,
I have this module for servo using I2C. It works. OK. But my servos are 8.5V high voltage high torque motors. Motors haves on PWM input side 4-8V.

Can I use this module for PWM? and Servo motors power supply have 8.5V? GND will be connected from Arduino to module and servo power supply.

Is there some danger? Or should I use some middle chip like ULN2803? Or simple diode from PCA9685 to servo PWM input? Just for sure, avoid damages of PCA9685 and Arduino when some electrical trouble in motor?

I am using adafruit library for this. It works fine.

Many thanks for ideas.

PS: no idea, if servo motor PWM input is isolated from servo power supply. And because servo eating 2A, can be a problem, when trouble.

I the servo controller states 4…8V input, then Arduinos PWM output probably is OK.
If you fear it is unsafe, add a 470 Ohm resistor in serial

A PCA9685 servo board already has 220ohm resistors in series with it's outputs.

Don't confuse servo power with servo data signals.