SN74LVC1G08: How to maintain the output amplitude of SN74LVC1G08 in the LMG1020EVM-006?

Makiko

Part Number: SN74LVC1G08
Other Parts Discussed in Thread: LMG1020EVM-006, LMG1020

Tool/software:

I would like to increase the output signal amplitude of the AND gate SN74LVC1G08 used in the LMG1020EVM-006 evaluation board.
The reason is that when trying to generate narrower pulses from the SN74LVC1G08, we found that the signal amplitude decreases.

How can we maintain the output amplitude while still generating narrow pulses from the SN74LVC1G08?

Best regards,

Makiko

2 months ago

0 Albert Xu1 2 months ago

TI__Mastermind 38225 points

Hi Makiko,

This might be a better question asked to the LMG1020 EVM team. They may be able to help debug this issue.

When you say narrower pulses, is the frequency increasing or you are getting a lower amplitude with a lower duty cycle?

0 Makiko 1 month ago in reply to Albert Xu1

Prodigy 40 points

Thank you for your reply!

Narrower pulse means frequency increasing. For example, 3ns width ->2ns width ->1ns width.

I would like to get narrowest optical pulse width!

0 Albert Xu1 1 month ago in reply to Makiko

TI__Mastermind 38225 points

Hi Makiko,

What frequency are you running at? With a 1ns width do you mean the frequency is ~1GHz?

Our devices are only rated to around 175-200 MHz

0 Makiko 1 month ago

Prodigy 40 points

Hi Albert,

We use SN74LVC1G08 as below. This image is quoted from the EVM User's Guide: LMG1020EVM-006.We are adjusting the frequency of the function generator to achieve the narrowest possible pulse width (1 ns) at the output.

0 Albert Xu1 1 month ago in reply to Makiko

TI__Mastermind 38225 points

Hi Makiko,

I am not sure how much more I can help you. Like before I would recommend posting to the group responsible for the EVM.

0 Makiko 1 month ago in reply to Albert Xu1

Prodigy 40 points

Dear Albert,

Let me change the question. If I want to increase the output signal amplitude of SN74LVC1G08, what should I do? Would raising the supply voltage of it be a solution?

Or would it be better to cool SN74LVC1G08 (improve heat dissipation) instead?

Thank you for your cooperation!

Best regards,

Makiko

0 Albert Xu1 1 month ago in reply to Makiko

TI__Mastermind 38225 points

Hi Makiko,

Yes, raising supply voltage would raise the amplitude, however, I don't believe this solves the core issue.

It seems you are following a usecase given by the EVM team which I do not have any knowledge of. I would ask to see if they have seen any issues with the current use case you are using.

0 Albert Xu1 1 month ago in reply to Albert Xu1

TI__Mastermind 38225 points

Hi Makiko,

I took a look at the EVM use case as well. What is the frequency you are inputting to the device?

As listed in the graph, you cannot have a frequency higher than 10MHz

0 Makiko 1 month ago in reply to Albert Xu1

Prodigy 40 points

Dear Albert.

Thank you for your big effort! I appreciate it.

I apologize for the significant delay in my reply due to the summer holidays.

We use 100kHz or 250kHz for inputting to the device. Do you have any advice or recommendations?

Best regards,

Makiko

0 Albert Xu1 1 month ago in reply to Makiko

TI__Mastermind 38225 points

Hi Makiko,

Without any scope shots I am not sure what else could be wrong. Have you reached out to the EVM team yet? As I mention before this is a usecase that they published. They may help troubleshoot more.

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SN74LVC1G08: How to maintain the output amplitude of SN74LVC1G08 in the LMG1020EVM-006?