SN74LVT125: I am not Getting proper 3.3v at output of sn74lvt125

VISHAL KALWANI

Intellectual 705 points

Part Number: SN74LVT125

I am Getting output voltage Range between 4v to 5v. And it also Goes in Negative Range.

And i have applied VCC 3.3V.

Input in Range of 3.3V to 4V.

I have attached the schematic and output Result.

My input in Range of 3.3 to 4V.

over 4 years ago

0 Emrys Maier over 4 years ago

TI__Guru* 96591 points

Hi Vishal, and welcome to the forums!

The signal you are showing has very significant ringing. This is a common issue when using a strong driver connected to a light capacitive load. Is this the response in your final system, or do you just have the device directly connected to an oscilloscope probe?

If you slow down your signal, I'm sure you will see that the ringing dies off relatively quickly and settles to 3.3V.

0 VISHAL KALWANI over 4 years ago in reply to Emrys Maier

Intellectual 705 points

This is final Response.I have test with no load and with 20mA load but getting same Result.

I am getting output voltage in Range between 4v and 5v.

0 Emrys Maier over 4 years ago in reply to VISHAL KALWANI

TI__Guru* 96591 points

Hi Vishal,
Try measuring with a differential probe -- I've found that the difference is massive.

You can also add a resistor to dampen the ringing - typically 26 to 330 ohms is used in series with the output.

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SN74LVT125: I am not Getting proper 3.3v at output of sn74lvt125