Frequent failure in 74HC595 IC

[Prabhakarankft]

Series resistor at all logic inputs can protect the

Adding 22E resistors series to all the IOs of 74HC595 will give any better results? Any suggestions

 

[FvM]

I was talking about inputs. 22R would be a bit low, rather 100 to 220R.

 

[Prabhakarankft]

I was talking about inputs. 22R would be a bit low, rather 100 to 220R.

Hi,
If We do so are there any loading issues will be? I hope adding more resistors increases total resistance and thus lowers current. Will the current be sufficient to operate the Input pin of 74HC595?? Hidden risk if any?

 

[KlausST]

Hi,

Will the current be sufficient to operate the Input pin of 74HC595??

Did you read about the '595 input current?
Then use Ohm's law to do some calculations.

Klaus

 

[Prabhakarankft]

Did you read about the '595 input current

As per the datasheet, I could fetch only Clamping currents. Does it mean indirectly it will accept a maximum of 20mA?
If is it so where could I get Min current requirement?

 

[KlausST]

Hi,

Don't look at the "absolute maximum values" / "Limiting values"
Look at the "Static characteristics"
It will be named "input current". Typical abbreviations: I_in, I_i, I_IL, I_IH .... or so.

Klaus

 

[Prabhakarankft]

Look at the "Static characteristics"
It will be named "input current". Typical abbreviations: I_in, I_i, I_IL, I_IH .... or so.

Hello,
I have checked the Static Characteristics of 74HC595. Where I could see Vol/Voh parameters. But I could not get the exact data you have mentioned. I am very well aware that every IC manufacturers will say the input current details in the datasheet.

The problem is they are mentioning Input current with other technical names. Datasheet as follows

https://assets.nexperia.com/documents/data-sheet/74HC_HCT595.pdf

 

[KlausST]

Hi,

I_I = Input leakage current

It´s there

Klaus

 

[Prabhakarankft]

I_I = Input leakage current

It´s there

Oh my God. Thanks for your valuable reply!