SN74LVC1G3157 S-pin pulldown

masahiko shimizu

Other Parts Discussed in Thread: SN74LVC1G3157

My customer is using SN74LVC1G3157 at Vcc=5V.
and It pulldown S-pin(Control input pin) to GND through 10k-ohm resister.
In P2 of D/S, IIK(Control input clamp current) is -50mA.
I think that The pulldown by 10k-ohm is not problem because 5V/10k-ohm is 0.5mA.
Is my idea correct? Could you give me advice?

Best regards,
Shimizu

over 11 years ago

0 C. Ryan Land over 11 years ago

TI__Genius 9860 points

This is correct as the current is much lower than the clamp current limit.

-Ryan

0 masahiko shimizu over 11 years ago in reply to C. Ryan Land

Guru 11235 points

Hi Ryan

Thank you for your spport.
and I have new two question.

1. Does B1 and B2-pin have the input voltage protection circuit for absolute voltage?
For example diode.
I think this IC have input voltage protection circuit for ESD.
But I'd like to know whether there is input voltage protection circuit for absolute voltage.

2. B1 or B2 pin is opened as termination of unused pin.
Is Open termination bad? Does IC break?

Best regards
Shimizu

0 masahiko shimizu over 11 years ago in reply to masahiko shimizu

Guru 11235 points

Hi Ryan

Please give me answer

Best regards

Shimizu

0 Chris Cockrill over 11 years ago in reply to masahiko shimizu

TI__Mastermind 46480 points

Hi Shimizu-san

The control pins will have a clamp diode to gnd only. The I/O pins will have a clamp diode to Vcc and to Gnd. So this means the I/O's cannot go above Vcc unless the current is limited.

I have attached a paper on how to tell if there are diodes.

Input diodes how to read.doc

0 masahiko shimizu over 11 years ago in reply to Chris Cockrill

Guru 11235 points

Ｈｉ　Ryan-san

Than you for your support.

I understood.

Best regards

Shimizu

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SN74LVC1G3157 S-pin pulldown