BOOSTXL-TLV8544PIR: TLV8544 current consumption is as high as120uA when PIR comparator output low

Hey Nicole, 

Is the customer using our design board or do they have their own board based on our design? 

All the best,
Carolina

Nicole,

Please try to install a fresh op amp back into the EVM board. This behavior is not expected. TLV8544 supply current is flat even in VOL or VOH state.

Hi, Caro, Ron, 

Thanks for replying. Customer is using their own board based on our design. 

What do you mean by install a fresh back?

Nicole,

Install a new (never used) part back into the board. 

Hi, Ron, 

Customer now have two projects using TLV8544 with same circuit and met similar issue. The IC was provided by us from ti store. 

Do you have test data to show the supply current of TLV8544 with comparator output high and low?

Nicole,

I have this old result from TLV8541, I suspect the quad would be the same.

Later this week, I can repeat this test on TLV8544.

Hey Nicole, 

Can you share the customer schematic?
If there is a propriety issue we can always move the thread to internal. 

All the best,
Carolina 

Schematic as attached.

Hi, Ron, 

Thanks. The picture you shared is the supply current for the first stage op amp, right?

In the boostxl board, TLV8544 is used for both amplification and comparator, I wonder, as a comparator, working in non-linear area, the supply may be different. 

Nicole,

The picture was the single channel version of the device, TLV8541

Here is supply current versus supply voltage for TLV8544 with all channels low.

To be complete, here is same thing except all channels high.

How are you measuring the supply current?

Hi, Ron, 

Thanks for providing the test data. I will check with customer for their measurement method. 

Did you test on the board of BOOSTXL-TLV8544PIR? Thanks!

Nicole,

I tested just a TLV8544 by itself, not on an EVM board.

Ron, 

That may be the difference. Could you test the supply current of boostxl TLV8544 PIR board? Thanks!

Hi Nicole,

oops, please remove cap C210! And remove C200! And remove C211! And I don't like the combination R1277 and C224. Either heavily increase R1277 and/or decrease C224.

Kai

Nichole,

Measuring on board has already been done it is 1.8uA total for whole board.

I'll start over; in your circuit, output low means no detection, idle state. You can only measure the total current, so it might not be the two comparators that are using all this power. Maybe one or both amplifiers are using the extra current. For that to happen, the amplifiers must be oscillating, working hard.

Kai is correct about C210, however you have three other capacitors shorting out your PIR signal; did you add those because the PIR was triggering too easily, false detections?

Check both pins 1 and 7 for oscillation. If either oscillate, there will be a lot AC voltage at pin 7 which will dump a lot of current into C224. This is where I think the high supply current goes.