TXV0106-Q1: The effects of overshoot on chip input pins

?? ?

Part Number: TXV0106-Q1

Tool/software:

Hi Teams：

Due to the limited PCB layout space, we have not placed termination resistors at the signal source end, and we also cannot reduce the driving capability of the output, which affects the signal's edge time. Consequently, there is significant overshoot at the chip's input pins. Will this have any impact on the chip? Below is our test waveform.

Best wishes！

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 316940 points

The absolute maximum ratings allow less than −0.5 V as long as the current through the clamping diode is less than 50 mA. This is probably the case (the forward voltage of the diode would be more than 0.7 V at 50 mA).

0 ?? ? over 1 year ago in reply to Clemens Ladisch

Prodigy 40 points

This is a high-speed RGMII signal output by the MCU, with IO driving capability at the mA level. The overshoot is likely due to impedance mismatch causing oscillations, and it probably won't reach a current of 50mA？

0 Michael Ikwuyum over 1 year ago in reply to ?? ?

TI__Guru 51106 points

Hi,

This is correct as we recommend to confirm the abs max current is not violated, thanks.

Best Regards,

Michael.

0 ?? ? over 1 year ago in reply to Michael Ikwuyum

Prodigy 40 points

The signal is driven by the MCU's IO and is a dedicated RGMII output IO. So, are there any risks in this scenario?

+1 Michael Ikwuyum over 1 year ago in reply to ?? ?

TI__Guru 51106 points

Hi,

Thanks for clarifying. The absolute max ratings are applicable to all cases.

You will have to verify if current of 50 mA is reached. However, this is typically not the case for overshoot / undershoot i.e. no risks if 50 mA is not exceeded, thanks.

Best Regards,

Michael.

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TXV0106-Q1: The effects of overshoot on chip input pins