DS90LV048A: Bias of pin 1&2 to make pin 15 go low - help

Michael T Schneider

Part Number: DS90LV048A

Team,

I need help on to bias the input of DS90LV048A, pin 1 and 2 so the output pin 15 to be at logic low.

Right now I have 75 ohms resistor connects between ground and pin 2 of U93 and 155 ohms resistor connects between +3.3V to pin 1 of U93.

Pin 1 measures about +1.8V and pin 2 measures about 0.8V but the output pin 15 is still at logic high 3.3V.

How can I make the output to go to logic low?

Below is snapshot for your reference.

0 Ikechukwu Anyiam over 3 years ago

Hi Michael,

-1V might be too much for the receiver. Can you try decreasing the differential voltage to less than -600mV?

Also, the DS90LV048A already has internal fail-safe biasing that makes the output high when there is no input. Why do you need it to be low?

Regards,

I.K.

0 Michael T Schneider over 3 years ago in reply to Ikechukwu Anyiam

Thanks I.K.,

I will try the Vid to -600mV.

We use the open input or fail safe feature to default the output to logic high to disable one of the function on the board.

But we also want to enable this function when the correct logic is applied to its input.

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