TUSB551: whether the OS pin can be pulled up or not?

Hi David,

Could you please share the detail reason? Thanks.

Frank

OS is a 2 state input with pull-up and pull-down resistor already integrated, so it can only support two input level, pulldown, or floating (with both internal pull-up and pull-down enabled, so the voltage is VCC/2). To support external pullup would require this input to be a 3 state input.

Thanks
David

hi David,

if it's 2 state input, it should accept the pull up, the pull up may belong to float. could you please help check it. Thanks.

Frank

Pull up belongs to the float, so you can leave OS floating, instead pull it up.

Thanks
David