SN74LVC8T245: SN74LVC8T245 and SN74LVC541A

Takashi Yamaguchi

Part Number: SN74LVC8T245
Other Parts Discussed in Thread: SN74LVC541A

Hi team,

My customer is using the SN74LVC8T245 and SN74LVC541A. Could you please help with the question below from the customer?

The customer is using the SN74LVC8T245 with VCCA=3.3V and the SN74LVC541A with Vcc=3.3V. Is it OK to input a High signal of about 4.5V to each of the /OE pins?

Regards,

Yamaguchi

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 242810 points

Yes; LVC inputs are overvoltage tolerant. See [FAQ] Can the input voltage (Vi) to my logic device be higher than the supply voltage (Vcc)?

0 Takashi Yamaguchi over 3 years ago in reply to Clemens Ladisch

TI__Genius 11040 points

Thanks for the answer. The SN74LVC8T245 and SN74LVC541A provide the following description in the data sheet. Is it still safe to input a high voltage(4.5V) to the OE?

SN74LVC8T245

"The SN74LVC8T245 is designed so that the control pins (DIR and OE) are supplied by VCCA."

SN74LVC541A

" OE should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. "

Regards,

Yamaguchi

0 Clemens Ladisch over 3 years ago in reply to Takashi Yamaguchi

Guru 242810 points

The datasheets mention V_CCA or V_CC because those define the minimum voltage for high-level signals. The voltage is still allowed to go higher. This is explained in the FAQ linked above.

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SN74LVC8T245: SN74LVC8T245 and SN74LVC541A