IWR6843: Could we use Industry grade part to replace Automotive grade for the design?

Jesse Wang

Part Number: IWR6843
Other Parts Discussed in Thread: TMP112,

Hi,

We follow the IWR6843ISK and its carrier board to design for industry product.

Since we don't need the automotive grade power IC, could we use below industry grade part number to replace the TI's design for cost saving?

1). To replace TPS7A5301QRGRRQ1 with TPS7A8400ARGRR.

2). To replace LM536253QRNLRQ1 with TPS62132RGTR/ TPS54335-2ADRCR/ LMR33630CRNX

Or, does TI have other industry grade DCDC chip for the design?

over 6 years ago

0 CHETHAN KUMAR Y.B. over 6 years ago

TI__Mastermind 25835 points

Hello,

Yes, you could change the component from Automotive to industrial grade components if you keep the electrical specs in the similar condition.
Please ensure voltage levels, noise, ripple are comparable.

TPS7A5301QRGRRQ1, TPS7A8400ARGRR are comparable for the 1V RF rail.

Specifically on LM536253QRNLRQ1 (Pre-regulator to LP8770) we would operate at higher switching frequency (2Mhz and above) this would produce lesser frequency harmonic content within the IF bandwidth (There could be some trade-off between efficiency loss due to higher switching frequency content). Also we would force the PWM output so that frequency components are predictable and doesn't dependent on load currents.
Hence we need to ensure PWM mode need to be ensured.

TPS54335 has Pulse Skipping for Light-Load Efficiency, this is not a desirable feature as it produces unpredictable low frequency harmonics which are very difficult to filter it out.
TPS6213 also has DCM mode of operation at lower load currents. This may not be favorable condition for radar.
TPS62132RGTR also has Power Save Mode at lower loads where it reduces switching frequency to improve the efficiency.

Thanks and regards,
CHETHAN KUMAR Y.B.

0 Jesse Wang over 6 years ago in reply to CHETHAN KUMAR Y.B.

TI__Intellectual 2285 points

Thanks, this helps.

0 AJ Cheng over 6 years ago in reply to CHETHAN KUMAR Y.B.

Genius 3615 points

Dear CHETHAN.
Good day.
Do you have any better suggestions to replace the TPS7A5301QRGRRQ1 and LM536253QRNLRQ1 non-automotive versions?
Or the discussion before is already the best choice. Thanks for kindly help~

0 AJ Cheng over 6 years ago in reply to CHETHAN KUMAR Y.B.

Genius 3615 points

Dear CHETHAN.

Good day.

Another problem is that reference Design has used the TMP112. But the price of TMP112 is too high.

Is there any other product with a cheaper specification that can be replaced? Thanks for help~

0 AJ Cheng over 6 years ago in reply to AJ Cheng

Genius 3615 points

Dear CHETHAN.

Good day.

This is the same case. Please kindly help confirm the question. Thank you~

0 CHETHAN KUMAR Y.B. over 6 years ago in reply to AJ Cheng

TI__Mastermind 25835 points

Hello,

TMP112 has both Automotive and Industrial part. Below link has industrial part.

http://www.ti.com/product/TMP112

And TMP112 is not a must have device for the IWR6843 operation. It's a good to have temperature sensor on board to measure the board temperature.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Jesse Wang over 6 years ago in reply to AJ Cheng

TI__Intellectual 2285 points

Hi Chethan,

Following your explanation, to replace the pre-regulator, LM536253QRNLRQ1, it seems at least 2MHz or higher PWM frequency is better to avoid harmonic from lower DCDC switching frequency.

If this is correct, could I use TPS62147RGXR (for example) with fixed switching freq.== 2.5MHz/ PWM mode? Is this ok?

0 CHETHAN KUMAR Y.B. over 6 years ago in reply to Jesse Wang

TI__Mastermind 25835 points

Hi Jesse Wang,

Sorry for the delay, I'm reviewing the datasheets, However you are right, higher PWM switching frequency is a desirable feature.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 CHETHAN KUMAR Y.B. over 6 years ago in reply to CHETHAN KUMAR Y.B.

TI__Mastermind 25835 points

Hi Jesse Wang,

TPS62147RGXR has only 2A load current, It's recommended to go with higher rated current (3 to 3.5A).

Also TPS62147RGXR has inferior thermal performance (RθJA) as compared to LM536253QRNLRQ1.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Jesse Wang over 6 years ago in reply to CHETHAN KUMAR Y.B.

TI__Intellectual 2285 points

Got it, thanks.

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IWR6843: Could we use Industry grade part to replace Automotive grade for the design?