LMH0318: Need level shifter for LMH0318 design in 3.3V system...

Peter Tseng

Part Number: LMH0318
Other Parts Discussed in Thread: LMH0302, LMH0346,

Dear Sirs,

My customer main chip is powered by 3.3V and they test with LMH0346 and LMH0302, all ICs on system are supply with 3.3V and work well.

However, they want to change to use LMH0318 that supply voltage is 2.5V, but main chip is supply by 3.3V.

May I need to use level shifter IC between I/O of main chip and LMH0318?

Thanks.

0 Nasser Mohammadi over 6 years ago

Hi Peter,

1). Of course, for 2.5V supply we need LDO that converts from 3.3V to 2.5V.

2). LMH0318 High speed inputs: You can AC couple of we don't need to worry about level shifter.

3). Low speed control signals inputs: You can use voltage divider to convert from 3.3V to 2.5V.

4). Low speed control signals outputs: LMH0318 outputs like LOCK indication or SDA are 3.3V tolerant.

Regards,, Nasser

0 Peter Tseng over 6 years ago in reply to Nasser Mohammadi

Dear Sir,

Thanks for your reply!

How about the high speed video signal output?

Does it still no need level shifter?

0 Nasser Mohammadi over 6 years ago in reply to Peter Tseng

Hi Peter,

Please AC couple high speed video signals using 4.7uF capacitors and there is no need for level shifting.

Regards,, nasser

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