SN74HC4851-Q1: Working current

Jasper Yao

Part Number: SN74HC4851-Q1
Other Parts Discussed in Thread: SN74HCS151-Q1

Hi team,

Could you help confirm the working current of SN74HC4851-Q1? Which is right? 50mA or 40uA as shown below.

The datasheet of SN74HC4851-Q1 can be seen in this link:/cfs-file/__key/communityserver-discussions-components-files/388/SN74HC4851_2D00_Q1.pdf

Thanks. Looking forward to your reply.

Best Regards,

Jasper

over 4 years ago

0 Rami Mooti1 over 4 years ago

TI__Mastermind 35648 points

Hey Jasper,

The first value is the absolute max rating. This is the maximum current that can be applied to VCC or GND before damaging the device. This is why it is listed in the absolute maximum ratings table.
The supply current is what the supply pin will see under the given conditions, which is why it is listed as a electrical characteristic. It defines how the device will work while the abs max sets the limitations of the device before failure.

Thanks,
Rami

0 Jasper Yao over 4 years ago in reply to Rami Mooti1

TI__Expert 6825 points

Hi Rami,

So is this supply current the maximum current that this device can output during normal operation?

Best Regards,

Jasper

0 Rami Mooti1 over 4 years ago in reply to Jasper Yao

TI__Mastermind 35648 points

Hey Jasper,

No this is what the supply is consuming during operation. This device itself is a passive analog multiplexer, meaning that it only allows singals to be passed through. The signals must be present from an external source and the mux will simply connect or disconnect the paths based in the control logic. It will not actually output or drive a signal on its own. Is the customer looking for a device to drive the signals or will a passive multiplexer work in their application?

Thanks, Rami

0 Jasper Yao over 4 years ago in reply to Rami Mooti1

TI__Expert 6825 points

Hi Rami,

So Does this device have a limit on the maximum through current? Yes, my customer is looking for device to drive signals.

Best Regards,

Jasper

+1 Rami Mooti1 over 4 years ago in reply to Jasper Yao

TI__Mastermind 35648 points

Jasper,

Yes, this is listed in the datasheet. I've highlighted it below

It seems that the customer will be more interested in a digital multiplexer. I would look into the digital multiplexers & encoders product page (maybe the demultiplexer page depending on the configuration direction) to find the proper solution. I did a quick search and the SN74HCS151-Q1 looks like a good place to start. It's an 8:1 option that will drive the output and has schmitt-trigger inputs as well. This device doesn't belong to my product folder so i'm going to go ahead and mark this as resolved and close this thread. But don't hesitate to ask anything else! I can loop in the appropriate team or you can ask a further question regarding a digital multiplexer or demultiplexer by starting a new thread on the logic and voltage translation forum.

Thanks!
Rami

0 Jasper Yao over 4 years ago in reply to Rami Mooti1

TI__Expert 6825 points

Hi Rami,

Really appreciate for your technical support. I will promote new device to customer. Thanks a lot. Happy new year!

Best Regards,

Jasper

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SN74HC4851-Q1: Working current