SN74LVT245B: Need to know the alternative IC suitable for the open drain input

shanthi s

Part Number: SN74LVT245B
Other Parts Discussed in Thread: TXS0108E, TXS0101, TXS0104E

Hi,

I have designed the circuit using the IC 74LVT245 to convert 5V to 3.3V. The output of hall sensor is open collector, that is connected to the input side of the 74LVT245.

In the no input (idle) state, the IC need to produce high voltage(3.3V) in my case. It is not achievable using IC 74LVT245.

So, Could you please help me to find a voltage convertor IC with internal pull up resistor in the input side with the same pin names and package as of 74LVT245? So it will avoid me to redesign the circuit.

Please reply back as soon as possible. Thanks in advance.

over 6 years ago

0 Emrys Maier over 6 years ago

TI__Guru* 96591 points

Hello Shanthi,
I don't know of any pin to pin compatible devices with the '245 that has internal pull-up resistors.

0 shanthi s over 6 years ago in reply to Emrys Maier

Intellectual 420 points

Ok can you please prefer the IC's for open collector input? Pin to pin compatible is not necessary if it is not available.

0 Emrys Maier over 6 years ago in reply to shanthi s

TI__Guru* 96591 points

There is no logic IC to fix this issue - just add a pull-up resistor.

0 shanthi s over 6 years ago in reply to Emrys Maier

Intellectual 420 points

I ll add external pull-up circuit in this circuit.

What IC will I use for the open collector input voltage conversion?could you please help for that?

0 Emrys Maier over 6 years ago in reply to shanthi s

TI__Guru* 96591 points

Why do you need a voltage translation on an open-drain circuit? Typically, open-drain outputs can be pulled-up to any voltage you need.

0 shanthi s over 6 years ago in reply to Emrys Maier

Intellectual 420 points

Hi,

My circuit input is having 3 state,

1. High - 5V,( Need to convert this to 3.3V)

2. Low - 0V,

3. Idle - need to be pull high or low.

For this i require the voltage conversion IC with inbuilt pullup/pulldown resistor.

While am using 74lvt245, During Idle input state the output holding its previous output. This is not suitable in my place.

0 Emrys Maier over 6 years ago in reply to shanthi s

TI__Guru* 96591 points

I understand. In the future, posting a schematic will help get to the answers much faster.

I would recommend using the TXS family of devices -- depending on how many lines you need you could use the TXS0101 (single line), TXS0104E (4 lines), TXS0108E (8 lines). These devices have internal 10kohm pull-up resistors.

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SN74LVT245B: Need to know the alternative IC suitable for the open drain input