TFP410: How can I select the 1.8V Input Signal Levels?

Matthew Chen

Part Number: TFP410

Hi team,

For TFP410, how can I select Adjustable 1.1 V to 1.8 V Input Signal Levels for universal graphics controller interface? Is there consideration when using the 1.8V level?

Thanks a lot

Matthew Chen

over 3 years ago

0 Brian Zhou over 3 years ago

TI__Guru*** 145435 points

VREF should be 0.55v to 0.9v for 1,8v input, nothing special for 1.8v or 1.1v.

0 Matthew Chen over 3 years ago in reply to Brian Zhou

TI__Intellectual 1400 points

Hi Brian,

Do you mean any Vref between 0.55 to 0.9V will make the IC receive 1.8V signal?

Thanks

0 Clemens Ladisch over 3 years ago in reply to Matthew Chen

Guru 316690 points

See section 7.3.2 of the datasheet. V_REF determines the switching threshold: Any input voltage below V_REF ±0.2 V will be interpreted as a low signal, any voltage above V_REF ±0.2 V as high. So V_REF should be half of the desired input voltage to maximize the noise margin.

0 Matthew Chen over 3 years ago in reply to Clemens Ladisch

TI__Intellectual 1400 points

Hi Ladisch,

Thanks,

If the vref is 0.9V, in the low swing mode, will all the signal input pin can receive 1.8V signal from FPGA?

Matthew

0 Clemens Ladisch over 3 years ago in reply to Matthew Chen

Guru 316690 points

Yes.

0 Matthew Chen over 3 years ago in reply to Clemens Ladisch

TI__Intellectual 1400 points

Thanks Clemens,

How about the VDD voltage for I2C and MSEN pin? Does it need to be 1.8V?

0 Clemens Ladisch over 3 years ago in reply to Matthew Chen

Guru 316690 points

The MSEN and SCL/SDA pins have open-drain outputs; you can pull them up to any voltage, up to 3.3 V.

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TFP410: How can I select the 1.8V Input Signal Levels?