ONET1151L: CML Output Current

xjonathanx xdufourx

Part Number: ONET1151L

Hi,

I'm trying to understand the 85mA p-p MODulation current spec, coming up with two questions:

1.) Is the 85mApp MODulation current spec referring to that deliverable to an external (10-Ohm) load, or, referring to the internal diff pair sink itself ?

If the spec refers to the internal sink, it seems only half of the current (42.5mA) is available at the load.

2.) What is the voltage compliance at the MOD pin?

Thanks for your help

over 6 years ago

0 Nasser Mohammadi over 6 years ago

TI__Guru* 93670 points

Greetings,
1). Yes your understanding is correct. 85mA is referring to delivering 85mA to the 10-ohm load.
2). 85mA into 10-ohm load means we have about 850mV peak to peak swing.
Regards,,nasser

0 xjonathanx xdufourx over 6 years ago in reply to Nasser Mohammadi

Prodigy 240 points

Thanks Nasser, for confirming the datasheet MOD current refers to that delivered to the load. I have a follow-up question: As the load resistance is increased, what is the maximum voltage that can be developed? For exqample, if the load resistance were increased, how much voltage can be expressed across the resistance before things collapse?

0 Nasser Mohammadi over 6 years ago in reply to xjonathanx xdufourx

TI__Guru* 93670 points

Greetings,
Based on our analyses, we should be able to increase resistance to about 50-ohm before output collapses. Maximum voltage would be at 1.5V.
Regards,,nasser

0 xjonathanx xdufourx over 6 years ago in reply to Nasser Mohammadi

Prodigy 240 points

Thanks for confirming the swing. I have a follow-up question:

When the ONET1151L input is pulsed logic TRUE, does OUT+ pulse negative or positive voltage into the 50-Ohm load ?

0 Nasser Mohammadi over 6 years ago in reply to xjonathanx xdufourx

TI__Guru* 93670 points

Greetings,
When input is pulsed logic TRUE OUT+ pulse negative. Through reg 0x00[2] you can change this polarity.
Regards,,nasser

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ONET1151L: CML Output Current