SN74LV1T126: Replacement for SN74LV1T126DCK

keita miyahana

Part Number: SN74LV1T126
Other Parts Discussed in Thread: SN74AVC1T45

Tool/software:

We are currently considering level shifters for converting 1.8V to 3.3V signals as an alternative to the SN74LV1T126DCK. Although we initially planned to use the SN74LV1T126DCK, its input high-level threshold of 1.39V does not meet our requirements, as the minimum high-level output voltage on the input side is only 1.24V.
Would you be able to recommend an alternative device that satisfies these specifications?

9 months ago

0 Joshua Salinas 9 months ago

TI__Mastermind 34820 points

Hello Keita,

What about the SN74AVC1T45? This is a dual-supply level translator with a VIH of 1.17V at 1.8V.

Regards,

Josh

0 Clemens Ladisch 9 months ago

Guru 322020 points

The SN74LVT1T126's input current is less than 1 µA, so the output voltage of your 1.8 V device will actually be near 1.8 V. See [FAQ] What is the output voltage (VOH or VOL) when the output current is X or the supply voltage is Y?

0 keita miyahana 8 months ago in reply to Joshua Salinas

Prodigy 50 points

Thank you so much, Joshua.
I would like to confirm one additional point regarding the SN74AVC1T45.
My understanding is that when the power supply voltage is not provided on one side of the device,
the output becomes high-impedance (Hi-Z). Is this correct?

Keita

0 Joshua Salinas 8 months ago in reply to keita miyahana

TI__Mastermind 34820 points

Hello Keita,

The VCC Disconnect feature is not available in the AVC family.

If you are looking for this feature, I would recommend the TXU0101 instead.

Regards,

Josh

0 keita miyahana 8 months ago in reply to Joshua Salinas

Prodigy 50 points

Hello Joshua
Thank you for your response.
The datasheet for the SN74AVC1T45 mentions a VCC isolation feature as shown below — is this incorrect?

VCC isolation feature – if either VCC input is at GND, then both ports are in the high-impedance state

Regards,
Keita

0 Joshua Salinas 8 months ago in reply to keita miyahana

TI__Mastermind 34820 points

Hello Keita,

That's correct, AVC1T45 has VCC Isolation meaning when one supply is referenced to GND, all I/Os enter Hi-Z.

From your previous post, it seemed you were talking about floating supplies which the AVC1T does not support.

Regards,

Josh

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SN74LV1T126: Replacement for SN74LV1T126DCK