TLV3501: TLV3501

robin gangopadhya18

Part Number: TLV3501
Other Parts Discussed in Thread: LM7705

I notice TLV3501 has -.03V possible at the -ve input in a comparator application.

Input in this circuit below has a sinusoid(vldet) with min amplitude of 100 mV with max at 200mV

You see any design safety issues with this circuit?

I am looking for fast comparator in a SOT23 pkg & this is the only one I found. I would prefer a split supply in SOT23 pkg but none I found.

Do you know one that would take +/- 5V split in a sot23 pkg & be this fast?

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Robin,

you could use a +/-2.5V supply voltage. Or the LM7705 could be added to provide a negative supply voltage of -0.232V.

Kai

0 robin gangopadhya18 over 5 years ago in reply to kai klaas69

Kai

Oh, this LM7705 is a very clever idea!

On the other hand, I do have -5v on the pcb but have very little real estate left.

Can I use a "resistive divider" to get -.232V? & put a cap across e.g. 0.1 uF?

A divider such as top value= 2.05k (.1%) and the lower value is 100 Ohm(.1%) , both of which we have in the board.

There would be clearly no current sinking into this node from TLV3501>

What do you think?

thnx much

0 kai klaas69 over 5 years ago in reply to robin gangopadhya18

Guru 140200 points

Hi Robin,

you will need a scheme which is able to absorb the supply current of TLV3501. So, your voltage divider is not low ohmic enough:

VP_6 is the voltage at the negative supply pin of TLV3501.

But you could use a Schottky diode to produce the negative supply voltage:

Kai

0 robin gangopadhya18 over 5 years ago in reply to kai klaas69

Kai

Love it!

thnx a lot.

0 Chuck Sins over 5 years ago in reply to robin gangopadhya18

Robin
looks like this is resolved, so I am closing out the thread
If any other questions come up, feel free to reply or create a new post
Chuck

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