SN74AXC4T774: Supply voltage

Vijetha Jain

Part Number: SN74AXC4T774

Does this level translator have any issues if same supply voltage is used on VCCA and VCCB? This is because I see one of inputs not pulled high inspite of its other side being high.

Thanks!

over 2 years ago

0 Clemens Ladisch over 2 years ago

Guru 243180 points

There is no restriction on the supply voltages.

Do you mean "input" or "output"? Please show a schematic.

0 Vijetha Jain over 2 years ago in reply to Clemens Ladisch

Prodigy 30 points

The supply used on VCCA and VCCB is 3V.
On output of Bx there is a pull up resistor. This signal is held high and on Ax it is low which has no pull up. Adding pull up on Ax will solve the problem but its not a clean way of doing it.

So my question is

- is same value of supply voltage cause any issue?

- is the pull up on both side necessary?

0 Clemens Ladisch over 2 years ago in reply to Vijetha Jain

Guru 243180 points

What is the value of the DIR pins? Please show a schematic.

Please note that input pins do not output a voltage.

0 Vijetha Jain over 2 years ago in reply to Clemens Ladisch

Prodigy 30 points

- DIR2 pin is pull high to VCCA.

- B2 signal is held high (it has pull up resistor)

The issue is A2 signal is low

+1 Clemens Ladisch over 2 years ago in reply to Vijetha Jain

Guru 243180 points

A2 is an input, which means that it must be driven externally.

If you want the signal to be high in this case, you need a pull-up resistor at the input. (The pull-up resistor at the output is needed only if you want a high voltage while the device is disabled or powered off.)

Logic

Logic forum

SN74AXC4T774: Supply voltage