SN65MLVD040: differential output error voltage format after hot swap

Jerry Chen

Part Number: SN65MLVD040

Hi there,

My customer used SN65MLVD040 as LVDS transmitter, converting single-ended to LVDS output. Sometimes after the receiver hot swap, one of the LVD040 transmitter ports output error voltage format as below shows. The inverting and non-inverting outputs are in the same phase(shown in CH2 and 4), and their common voltage was changed to zero. Powering up it again can recover to normal differential output.

I would like to know the possible mechanism that the internal circuit is influenced by hot swap for this symptom. Then, I will ask customer to add work-around to protect the susceptible part of this device.

Thanks.

over 5 years ago

0 Ikechukwu Anyiam over 5 years ago

TI__Mastermind 35130 points

Hi Jerry,

Can you share the image again? It looks like the other channel was cut off. Additionally, can you include the input signal?

Regards,

I.K.

0 Jerry Chen over 5 years ago in reply to Ikechukwu Anyiam

TI__Expert 5110 points

Hi I.K.

Below is the differential output of the channel, the non-inverting and inverting outputs are in the same phase, and common voltage is zero. Other channels are fine. After the receivers are disconnected from other channels. This channel recovers to normal operation.

It might be some system issues influence the internal circuit. I would like to know the possible internal operation, then I will find out which external cause triggers it.

Thanks

0 Jerry Chen over 5 years ago in reply to Jerry Chen

TI__Expert 5110 points

Hi team,

Is there any comment for this?

Thanks.

0 Ikechukwu Anyiam over 5 years ago in reply to Jerry Chen

TI__Mastermind 35130 points

Hi Jerry,

Sorry for the delay. This is an old device so I don't have information about the device internal circuit. However, if this only occurs after hot swapping and is fixed with a reset, then it looks like hot swapping is somehow putting the device in a bad state. At any point in time during the hot swap does your design violate any of the absolute maximum ratings listed in the data sheet?

Regards,

I.K.

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SN65MLVD040: differential output error voltage format after hot swap