LSF0101: Add LSF0101 at clock output for voltage level shift function

Ben Kuo

Part Number: LSF0101
Other Parts Discussed in Thread: 2N7001T, SN74AXC1T45

Dear team,

We plan to add level shift function at TI clock gen output to translate voltage level from 1.8V to 3.3V. (CMOS/ single-end type)

However, the output voltage will up to 2.1V at clock gen output.

My question is,

Is there any risk if we connect Vref_A to 1.8V of LSF but the input signal voltage level up to 2.1V? (input signal voltage not the same as Vref_A).

Thanks,

Ben

0 Clemens Ladisch over 2 years ago

Guru 260230 points

The LSF I/Os are overvoltage tolerant.

But the LSF has open-drain outputs. For a clock signal, it might be a better idea to use a buffered translator like the 2N7001T or SN74AXC1T45.

0 Ben Kuo over 2 years ago in reply to Clemens Ladisch

Thanks for your information.

But LSF part is recommend by clock gen datasheet.

one more question here, does SN74AXC1T45 can support both 25MHz and 50MHz signal speed?

0 Clemens Ladisch over 2 years ago in reply to Ben Kuo

Guru 260230 points

For 1.8 V/3.3 V, the SN74AXC1T45 supports 500 Mbps.

The clock generator datasheet was written before the 2N7001T and SN74AXC1T45 were introduced.

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