TLV1702: Dual comparators not working simultaneously.

Himanshu Tanwar

Part Number: TLV1702
Other Parts Discussed in Thread: , TLV7022

We are using samples TLV1702-Q1 for our design with 5V supply and pull up resistor of 1k ohm.

Of the dual comparators, one is working fine but the second gives a high output of around 2-2.1V continuouly.

We've tried with multiple samples but the result is same, though for sure the design is correct, and also the design self verifies by the fact that sometimes the first and sometimes the second shows this behaviour.

Is there any specific reason for why this is happening?

over 4 years ago

0 kai klaas69 over 4 years ago

Guru 140200 points

Hi Himanshu,

what happens when you increase the pullup resistor to 5k1?

Can you show a schematic?

Kai

0 Paul Grohe over 4 years ago

TI__Guru 52776 points

Hello Himanshu,

Can you provide a schematic and/or scope photos of "good" and "bad" operation?

This is not expected operation of the device.

What else are the outputs driving? Is there another load to GND? What is the trigger frequency? Is the TLV1702 getting warm? Are there any transients on the inputs?

A 1k pull-up resistor is 5mA at 5V - which is a bit on the high side for a micropower comparator. Are you sure it is not mistakenly a 100 ohm resistor? As Kai suggested, try increasing the pull-up resistor value and see if it makes a difference.

Something in the design is not correct...It should not be doing this...Have you tried another comparator, such as the TLV7022?

0 Chuck Sins over 4 years ago in reply to Paul Grohe

TI__Mastermind 24300 points

We have not received a response on this thread in a while, so I will be closing the thread. If you need further assistance, feel free to to reply or open a new thread.

Thanks,

Chuck

0 Himanshu Tanwar over 4 years ago in reply to Paul Grohe

Prodigy 20 points

Hi Paul

Yeah somehow the optocoupler attached to one of the two was damaged and it changed the loading conditions of that one which was more frequently giving bad response but yeah the second is still not quite understood since these weren't even connected. But we tried with a new ic after changing the optocoupler and somehow everything seems fine for now.

Thanks for the response.

0 kai klaas69 over 4 years ago in reply to Himanshu Tanwar

Guru 140200 points

Hi Himanshu,

these are good news :-)

Good luck!

Kai

0 Chuck Sins over 4 years ago in reply to kai klaas69

TI__Mastermind 24300 points

Thanks for confirming.

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TLV1702: Dual comparators not working simultaneously.