all MAX14912 outputs in push-pull and parallel mode switch @duty=30% while INPUT is always high.

Dear All,

I am a newbie. 

I have a problem on my prototype with MAX14912 devices onboard. My schematic is below, following MAX14912EVKIT schematic.

I use external Vdd=24V to supply the device, using V5=5Volts and VL=3,3V, too. I use the device with push-pull outputs and parallel mode.

So: PUSHPL =3V3; EN=3V3: SRIAL =0;BUKEN=0, to set the wished functional mode. I kept the SPI port for diagnosis only.

I drive IN1...IN8 with a 3V3 microcontroller and I observe the outputs OUT1...OUT8 with a load of about 3,3mA each one. ...A little load to lite on just a led for each outputs.

The problem is the following.

If INx=0V the output OUTx is correctly near 0V, as written on datasheet.

If INx=3V3 (fixed) I observe OUTx output switch between 24V and 0V with a duty of about 30%.

Please, could explain me how could I get a stable 24Vdc output while input is 3V3 ?

Thank you very much for your availability.

Best Regards, Davide.