Output levels of K8055

[Tusor]

Hi,

I just tested my K8055 with another circuit I created. I wanted to use the digital outputs of the K8055 for switching and the PWM-signals for a buck converter which is going to drive motors. But I have still one question: What is the output-Voltage of the digital-outputs? I thought it would be 5V like the USB-Voltage, but I just got app. 1.1V out.
For the PWM-Signal I found here in the forum, that it has a frequency of 23kHz. But which voltage levels does it use?
Thanks for your help.

Tusor

[VEL436]

There is no voltage coming out from the digital and the PWM outputs. Those are open collector outputs. You have to add there pull-up resistors.

See the thread: forum.velleman.be/viewtopic.php? … 7f798506c5

en.wikipedia.org/wiki/Open_collector

One useful property is that the pullup resistor need not be connected to a voltage similar to that of the chip supply (Vcc); a lower or higher voltage can be used instead.

[Tusor]

thanks for the response. I just found a newer version of the manual of the K8055. There is this problem explained much better. So I think now I know what to do.