LSF0102: Will this work for the fan tacho and pwm pins

Ashutosh Nahar

Intellectual 640 points

Part Number: LSF0102
Other Parts Discussed in Thread: ASH, SN74LVC2T45, SN74AVC2T45, , TXS0102

I want to use LSF0102DCUR part for the fan pwm and tacho pins which is pull up to 5volt.

Can i use this part.

Thanks

Ash

over 6 years ago

0 ShreyasRao over 6 years ago

TI__Guru 61570 points

Ashu,

LSF is a passive translation device, which doesnt provide any drive current of its own unlike the active translation devices like the SN74AVC2T45 or the SN74LVC2T45.
Would the fan tacho pins require current drive or is it enabling or disabling the device ( which I assume would be hi-z pins and not require much drive strength)? What is the input driver device voltage level?
For a 5V translation requirements, consider using the SN74LVC2T45 which provides up to 32mA per channel drive current.

0 Ashutosh Nahar over 6 years ago in reply to ShreyasRao

Intellectual 640 points

Hi Shreyas,

Thanks for the reply.

Tacho signal is driven by the fan and pwm signal is driven by the processor.
The processor side voltage is 1 volt and fan side it is 5v signal.
I will translate from 1 volt to 5 volt.

Can i use the LSF0102DCUR.

Thanks
Ash

0 ShreyasRao over 6 years ago in reply to Ashutosh Nahar

TI__Guru 61570 points

Ash,

You can use LSF0102 as there are no active drive translators which does 1V to 5V.

0 Ashutosh Nahar over 6 years ago in reply to ShreyasRao

Intellectual 640 points

Thanks for the confirmation.

Currently I am using MAX14591 part.

Can you please confirm that I can replace max part with TI LSF0102DCUR part.

Thanks
Ash

0 ShreyasRao over 6 years ago in reply to Ashutosh Nahar

TI__Guru 61570 points

Ash,
The MAX device seems that it can be replaced by TXS0102, however, it doesnt support 1V.
Using the LSF0102, you would need the additioanal pullup on the IO lines.

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LSF0102: Will this work for the fan tacho and pwm pins