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eli

Guru 13485 points

Other Parts Discussed in Thread: SN74LVC8T245, LSF0108, SN74ABT126, SN74LVC2T45, SN74LVC1T45

looking for translator that translate from 5v to 3.3V and opposite that comply to TTL-5V?

If so can it work in 50MHz clock?

Is LVCC4245A is the right solution?

over 8 years ago

0 Emrys Maier over 8 years ago

TI__Guru* 97476 points

Hi eli,
We have many devices that can down-translate from 5V to 3.3V or up-translate from 3.3V to 5V. Can you tell me more about the application so I can suggest a part?

How many channels are there?

Is each channel unidirectional (signal always goes the same direction), directional controlled (signal changes directions with a direction signal), or auto-bidirectional (signal changes directions randomly with no direction signal)?

What type of driver is on each side of the device (open-drain or push-pull)? How much current can the driver source/sink?

What is the capacitive loading on each port (approximate values are fine -- 5pF, 15pF, 50pF, etc)?

0 eli over 8 years ago in reply to Emrys Maier

Guru 13485 points

Hi
Need to check,but should be 8 bit,,directional control or auto-bidirectional.
Need to be 50M

0 Emrys Maier over 8 years ago in reply to eli

TI__Guru* 97476 points

Direction controlled is going to be far better signal quality, so I would recommend going that way if at all possible.

The SN74LVC8T245 will work very well if it is direction controlled.

If it autobidirectional, then we are essentially left with LSF0108. This device requires a strong driver (~10mA sink current on each side) and low capacitance (~15pF on the 5V side) to operate at 50 MHz. I would recommend watching the video series we have on the LSF if you plan to use it: training.ti.com/LogicMinute

0 eli over 8 years ago in reply to Emrys Maier

Guru 13485 points

Will the SN74LVC8T245RHL, SN74ABT126PWR, work at 50MHz

0 Emrys Maier over 8 years ago in reply to eli

TI__Guru* 97476 points

Both of those devices will work at 50 MHz, however the SN74LVC8T245 is the clear choice (which I already stated above) because the SN74ABT126 requires up to 30mA of Icc, ~2000 times more current than the LVC device due to it's bi-CMOS architecture.

0 eli over 8 years ago in reply to Emrys Maier

Guru 13485 points

Thanks
How I can know the typ speed it can work?

0 Emrys Maier over 8 years ago in reply to eli

TI__Guru* 97476 points

Hi eli,
We typically use a device in the same family to compare against. In this case, the SN74LVC1T45 and SN74LVC2T45 are built on the same technology. I would expect the SN74LVC8T45 to be slightly reduced due to the number of channels, but not by much. The device should easily be able to work at 360 Mbps (180 MHz).

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