SN74LVC541A: Vcc = 5V is acceptable?

Noriyuki Takahashi

Part Number: SN74LVC541A
Other Parts Discussed in Thread: SN74HC541, SN74AVC16T245, SN74LVC16T245

Hi team

Looking at the datasheet P.1, there is a description "Support Mixed-Mode Signal Operation on All Ports (5-V Input/Output Voltage With 3.3-V VCC)".

Does this mean following things are acceptable?

case 1. Input voltage = 5V, output voltage = 3.3V at Vcc = 3.3V

case 2. Input voltage = 3.3V, output voltage = 5V at Vcc = 5V

I guess the case 1 is no problem. How about the case 2?

If the case 2 is not good, are there any devices that can satisfy both cases?

Regards,

Noriyuki Takahashi

over 7 years ago

0 Emrys Maier over 7 years ago

TI__Guru* 97046 points

Hello Takahashi-san,
Case 1 will work fine.

Case 2 is not recommended for any CMOS device since the input would be very low, causing shoot-through current on the CMOS inputs.

To do this, I would recommend adding a dual supply voltage translator (for example, SN74AVC16T245) prior to a 5V capable '541 function device such as the SN74HC541.

0 Noriyuki Takahashi over 7 years ago in reply to Emrys Maier

TI__Genius 10980 points

Thanks, Emrys.

It seems that SN74AVC16T245 does not support 5V.
Are there any device supporting 5V?

Regards,
Noriyuki Takahashi

0 Emrys Maier over 7 years ago in reply to Noriyuki Takahashi

TI__Guru* 97046 points

My apologies Takahashi-san,
I should have said SN74LVC16T245.

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SN74LVC541A: Vcc = 5V is acceptable?