Single ended LVPECL input to LVTTL

raquib akolawala

Other Parts Discussed in Thread: SN65LVELT23

Hi,

I am currently designing a circuit in which I get a Single ended LVPECL output signal from a device which I need to convert to single ended LVTLL signal.

The device from which I am getting a single ended LVPECL signal is AFBR5803 (pin4)

The single ended LVTTL signal I will give to an FPGA.

For the same I intend to use SN65LVELT23.

But nowhere in the datasheet it is mentioned that the SN65LVELT23 can accept single ended input, everywhere it is mentioned as differential inputs. I wanted to know whether the device can accept single ended input? If yes can you please mention the required interface for the same.

Else can you provide me an alternate solution to this problem.

Thanks Regards

Raquib Akolawala

over 12 years ago

0 Michael Peffers over 12 years ago

TI__Mastermind 20820 points

Hi Raquib,

You can use the SN65LVELT23 to convert single ended LVPECL to single ended LVTTL. This is accomplished by tying one of the differential pair signals to 2V which is the common mode voltage (V_CM) of LVPECL. This allows the single ended LVPECL signal to swing around its typical V_CM value. Please let me know if you have any additional questions?

Regards,

Mike

0 raquib akolawala over 12 years ago in reply to Michael Peffers

Intellectual 280 points

Hi Mike,

Thanks for the Solution.

I have asked for samples and will try out the same, and include it in the design

Additionally I had an idea If I could use a comparator and with reference voltage at 2V and the other end is my single ended LVPECL signal. Theoretically I think it should work. I am going to try this out for curiosity's sake. Please can you let me know your suggestion/comments about the same.

Thanks Regards

Raquib Akolawala

0 Michael Peffers over 12 years ago in reply to raquib akolawala

TI__Mastermind 20820 points

Hi Raquib,

A comparator would work as well. Essentially you are using the SN65LVELT23 as a comparator in this configuration.

Regards,

Mike

0 raquib akolawala over 12 years ago in reply to Michael Peffers

Intellectual 280 points

Thanks Mike

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Single ended LVPECL input to LVTTL