LDC1612: Current drawn by Internal oscillator

Art Mecina

Part Number: LDC1612

Hello Guys,

Good day.

We have a customer asking for the current drawn by the internal oscillator of LDC1612. He is curious because he is currently using an external oscillator and its drawing current too high for his power budget of 4.5mA.

Thanks in advance!

Art

over 4 years ago

0 Arjun_Prakash over 4 years ago

TI__Expert 7599 points

Hi Art,

Can you describe more information on the request ?

The current consumption of the LDC1612 is dependent on the Sensor drive current which is 1.5mA or 6mA (typical)

Is the measurement inclusive of the sensor current ?

Can you describe more on how they are measuring the current ?

0 Art Mecina over 4 years ago in reply to Arjun_Prakash

TI__Genius 16585 points

Thanks Arjun for looking into this.

I will get back to you as soon as I got their confirmation.

Art

0 Art Mecina over 4 years ago in reply to Arjun_Prakash

TI__Genius 16585 points

Hello Arjun,

Below are the additional information from the customer:

Their concern is regarding the current consumption of the on-chip clock. His total current consumption was his whole system. He just need to know the current consumption of the internal oscillator block on the LDC1612.

Another question he has is will all the blocks on the LDC1612 operate down to -55 DegC? He understand that the performance in the datasheet is guaranteed down to -40 but he is looking for operation below that.

Thanks!

Art

0 Art Mecina over 4 years ago in reply to Art Mecina

TI__Genius 16585 points

Hello Arjun,

Just like to update regarding the customers follow-up inquiry.

Thanks!

Art

0 Arjun_Prakash over 4 years ago in reply to Art Mecina

TI__Expert 7599 points

Hi Art,

The current consumption as per the datasheet is 2.1 mA which is a typical parameter. Current consumption with Internal clock vs external clock is not a tested parameter. The current consumption and the source is primarily dependent on the sensor drive current and for optimization the current consumption on the sensor drive needs to be considered.

If customer is looking to explore options to reduce the power consumption we do have app note describing the techniques. Here is the link

The LDC1612 is rated from -40C to 125C. This is not intended to work below -40C. What is the application here ?

0 Art Mecina over 4 years ago in reply to Arjun_Prakash

TI__Genius 16585 points

Hello Arjun,

The device will be use for detecting latching conditions of a 15-5 PH lock.

They would like to know what functionality would be reduced below -40 deg.?

Also, I just like to confirm that this device is non-automotive right?

Do we have an equivalent device that they can use for a much wider temp range? (an auto version perhaps).

Thanks!

Art

0 Arjun_Prakash over 4 years ago in reply to Art Mecina

TI__Expert 7599 points

Hi Art,

Please take a look at the LDC1612-Q1 device. It can operate from -40C to 125C.

As the device is not rated beyond -40C we have not tested any parameter or have done analysis to point out what functionality works or breaks.

0 Art Mecina over 4 years ago in reply to Arjun_Prakash

TI__Genius 16585 points

Hello Arjun,

By the way, while the customer is working on this he encountered an issue where he is using ZMR330FTA to power the LDC1612, and something seems to be consistently "shorting out" the LDC1612.

Everything powers up OK, then after about 1-2 minutes the unit draws lots of current and shuts down. VCC and GND on the part are shorted. Aside from workmanship, is there anything that can cause the LDC1612 to do this?

Do you prefer to create a new ticket for this? Just let me know.

Thanks!

Art

0 Arjun_Prakash over 4 years ago in reply to Art Mecina

TI__Expert 7599 points

Hi Art,

Please post another E2E post for the high current draw. Thanks.

0 Art Mecina over 4 years ago in reply to Arjun_Prakash

TI__Genius 16585 points

Hello Arjun,

Just raised a separate ticket here: https://e2e.ti.com/support/sensors/f/1023/t/927365

Thanks!

Art

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LDC1612: Current drawn by Internal oscillator