SN7404: The signal voltage level conversion IC recommendation

Eric Qi

Part Number: SN7404
Other Parts Discussed in Thread: UCC27517, TXH0137D, CD40109B, TXH0137D-Q1, UCC27424

Hi，

I am looking for a voltage level conversion chip or buffer.

I need to convert my signal voltage from 3.3V to 15V.

SN7404D seems not to be the right choice, please help recommend a logic chip or solution.

The conversion time should preferably be less than 200ns.

Thanks.

0 Clemens Ladisch 7 months ago

Guru 281410 points

How many channels?

For a single channel, UCC27517.

0 Eric Qi 7 months ago in reply to Clemens Ladisch

I need 16 channel in total.

And the signal is PWM siganl to drive IGBT, the frequency is 20KHz.

Thanks

0 Eric Qi 7 months ago in reply to Clemens Ladisch

CD40109B and TXH0137D, which is appropriate?

And I have a question, for TXH0137D, the datasheet only provide the parameter of VIH's minimum value.

I think this is inappropriate for application, also i know the input type is CMOS.

My question is if the VCC=15VDC, does the input can support 3.3V logic signal?

Thanks.

0 Malcolm Lyn 7 months ago in reply to Eric Qi

The TXH0137D is more appropriate here. Yes it can translate from 3.3V to VCC.

Best,

Malcolm

0 Clemens Ladisch 7 months ago in reply to Malcolm Lyn

Guru 281410 points

The TXH0137D-Q1 has open-drain outputs, so the high-level output voltage is only weakly driven by the pull-up resistor.

To drive gates, you should use gate drivers, e.g., 8× UCC27424.

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