SN74LVC373A: Up voltage translation

SimonF

Part Number: SN74LVC373A
Other Parts Discussed in Thread: LSF0108, TXB0108

Hi Team,

is there a part like SN74LVC373a which can shift the voltage up from 1.8V input to 3.3V output? If not can you recommend a level shifter which would fit?

Thank you for your time!

Best regards

over 7 years ago

0 Emrys Maier over 7 years ago

TI__Guru* 96591 points

I'm afraid I don't know of a '373 function device that can also do that level shift. I am moving this post to our translation forum to see if anyone else knows of a '373 device that I didn't find.

Before I recommend a level shifter, can you tell me about the data signals?

How fast are they?

What is driving them (ie maximum drive current, V_OH/V_OL)?

Is there a power budget?

0 SimonF over 7 years ago in reply to Emrys Maier

TI__Expert 3050 points

Hi Emrys,

they would need a bidirectional 100Mhz up level translator for 1.8V to 3.3V. Do you think the LSF0108 could work there?

Best regards

0 Clemens Ladisch over 7 years ago in reply to SimonF

Guru 244220 points

Why bidirectional? A latch would imply unidirectional signals.

0 SimonF over 7 years ago in reply to Clemens Ladisch

TI__Expert 3050 points

The address/data signals are directly routed to the data pins of the flash. Additionally they are routed to the latch. The latch is controlled with a extra line to "filter out" the addresses and rout them to the address pins of the flash.

0 Clemens Ladisch over 7 years ago in reply to SimonF

Guru 244220 points

I fear that I now understand even less about your problem.

Please show the schematic.

0 SimonF over 7 years ago in reply to Clemens Ladisch

TI__Expert 3050 points

It looks somehow like this:

0 Clemens Ladisch over 7 years ago in reply to SimonF

Guru 244220 points

If you have a direction signal, you can use a direction-controlled voltage translator.

0 SimonF over 7 years ago in reply to Clemens Ladisch

TI__Expert 3050 points

Hi Clemens,
unfortunately there is no direction signal.
Best regards
Simon

0 Clemens Ladisch over 7 years ago in reply to SimonF

Guru 244220 points

Then check out the TXB0108. But at 1.8 V, you do not get more than 60 Mbps; this is the price you pay for the automatic direction sensing.

The LSF0108 is said to go up to 100 MHz, depending on the load.

0 SimonF over 7 years ago in reply to Clemens Ladisch

TI__Expert 3050 points

And LSF0108 would not work for this?

0 Emrys Maier over 7 years ago in reply to SimonF

TI__Guru* 96591 points

The LSF0108 should work for the translation portion. At 100 MHz your load capacitance and pull-up resistor selection will be critical to ensure everything works properly. Please take a look at our application note "Voltage-Level Translation With the LSF Family"

The two keys to high speed translation with the LSF family of devices are keeping the higher-voltage traces as short as possible and choosing the smallest resistors possible while staying within the output current limits of your driving device.

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SN74LVC373A: Up voltage translation