TPS1HC30-Q1: RSNS calculate

Sky Kao

Part Number: TPS1HC30-Q1

Tool/software:

I have some doubts about the RSNS calculation. I referred to the example in the datasheet, but I'm a bit confused about two points.

KSNS=1814, but the previous specification says 1560.
The calculation in the example (5 V – 1 V) × 1814 / 6 A ≤ ≅1 kΩ is also not satisfied. Are the above two points written incorrectly?

Given my requirements, how should I design RSNS? VDIAG_EN=3.3V ; ILOAD,max=2A ; ILOAD,min =20 mA ; VADC,min=5 mV

over 1 year ago

0 Alan Whitehead over 1 year ago

TI__Genius 10785 points

Hello,

The 1k resistor in this application was used as an approximation to meet the requirements in the application.

(5 V – 1 V) × 1560 / 6 A ≤ RSNS

1040 ≤ 1k

For your application

(3.3 V – 1 V) × 1560 / 2 A ≤ RSNS

1794 ≤ RNSS

Best Regards,

Alan

0 Sky Kao over 1 year ago in reply to Alan Whitehead

Intellectual 630 points

Hi Alan

RSNS ≤ VADC,min × KSNS / ILOAD,min

For this formula, if KSNS = 1560 and using the example from the datasheet:

5mV * 1560 / 20mA = 390

Am I misunderstanding something in this calculation?

In the datasheet, KSNS is specified under a condition of 1.5A.

Is there a KSNS specification for 0.5A? Also, is there a KSNS specification for ILOAD,min?

If possible, could you provide the optimal KSNS range?

The customer is urgently trying to confirm production conditions for the production line.

Thank you!

0 Alan Whitehead over 1 year ago in reply to Sky Kao

TI__Genius 10785 points

Hello,

So sorry for the confusion I followed up to verify the equation in the datasheet. There is a typo!

It should be:

VADC,min × KSNS / ILOAD,min ≤ RSNS ≤ (VSNSFH – VHR) × KSNS / ILOAD,max

For your application the range should be:

5mV * 1560 / 20mA ≤ RSNS ≤ (3.3 V – 1 V) × 1560 / 2 A

390 ≤ RSNS ≤ 1794

Hope this clears the confusion.

Best Regards,

Alan

0 VIOLA LIAO over 1 year ago in reply to Alan Whitehead

Prodigy 120 points

Hi Alan,

sorry, so the KSNS=1814 on the datasheet is incorrect.
we need to use 1560 to calculate the RSNS, right?

0 Alan Whitehead over 1 year ago in reply to VIOLA LIAO

TI__Genius 10785 points

It is recommended to use what is in the electrical characteristics.

KSNS = 1560

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TPS1HC30-Q1: RSNS calculate