SN74LVCZ244A: When the input is undefined.

Kengo.Y

Guru 11525 points

Part Number: SN74LVCZ244A

Hi team.

SN74LVCZ244A will be used as 5V to 3.3V level shifter.

The input may become unstable when the power supply of 5V may be list.

Is there any problem with SN74LVCZ244A?

Sincerely.

Kengo.

over 7 years ago

0 Clemens Ladisch over 7 years ago

Guru 327050 points

If there is power, then the input must have a valid logic voltage level (< V_IL, or > V_IH).

In any case, the input voltage can be higher than the power supply (up to 6.5 V), so if V_CC = 0 V, all input voltages are allowed.

0 Dylan Hubbard over 7 years ago in reply to Clemens Ladisch

TI__Mastermind 48355 points

Hi Kengo,

As Clemens said, if the device is powered than it will need valid logic levels at the inputs. If you expect them to float if the 5 V supply is lost I would add in some really weak pull-downs to hold a logic state.

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SN74LVCZ244A: When the input is undefined.