ADC128s102 IOL output current

Jose Romero

Other Parts Discussed in Thread: ADC128S102

I am using the ADC128s102 and I need to put a voltage divider on the output from 5V to 3.3V. The IOH or Isource is indirectly specified in page 5 of the datasheet as 200uA in the VOH section. This seems very low. Can you tell me what the maximum Isource current is for the DOUT pin.

over 11 years ago

0 Michael Stout over 11 years ago

TI__Genius 16890 points

The DOUT should be able to supply more current. However, as the source current from the DOUT pin increases it will decrease the decrease the Voh level though.

Another option would be to put 3.3V on the VD pin, this will make the DOUT pin output range 0 to 3.3V.

Mike

0 Jose Romero over 11 years ago in reply to Michael Stout

Prodigy 120 points

Hi Mike, thanks for your reply. I was hoping to get a little more of a concrete answer. What is the maximum source current I can draw without causing any damage to the part?

Jose

0 Michael Stout over 11 years ago in reply to Jose Romero

TI__Genius 16890 points

I talked with someone who worked on this product when it was developed. They did not measure how much current it could source. He thought that it should be able to source 1mA without a problem, but the maximum Voh will change as I indicated in the previous post.

Mike

0 Jose Romero over 11 years ago in reply to Michael Stout

Prodigy 120 points

Thanks Mike, that answers my question

0 Carson Baisden over 10 years ago in reply to Michael Stout

Prodigy 20 points

Does the device limit output current? I have 100 Ohms in line with the output...I am curious the result if the 100Ohms ends up shunting the output to ground will the A/D try to deliver 50mA (wtih Vcc=5V)? It will likely be lower since Voh will decrease.

Ultimately, will the device be damaged if the output is terminated with 100Ohms to ground and the output is held high?

Carson

0 Michael Stout over 10 years ago in reply to Carson Baisden

TI__Genius 16890 points

Hi Carson,

Yes, there is the possibility of the part being damaged. The SDO pin will try to supply the 50mA current in your example. This will exceed the allowable power dissipation. The Abs Max specs of Package current and pin current that it will also be exceeded.

Mike

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ADC128s102 IOL output current