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DRV81602-Q1: INX pins

navya diddi
Prodigy 90 points
Part Number: DRV81602-Q1
Other Parts Discussed in Thread: DRV8210

Tool/software:

Dear team,

i am using the replacement of Infenion IC part:- TLE75602ESDXUMA1 with DRV81602-Q1.

In infenion part the IN0 PINS has max limit of 7.6kohm of pin current(5.5v@0.75mA),So i kept 10kohm series resistor to that pin and connected microcontroller.

When i want to replace with TI IC the   INx PINS has max limit of 7.6kohm of pin current(5.75v@0.75mA) as below picture but the recommendation is 4.7kohm as per below tables.

so what is the series resistor recommendation for this INX pins?

Best regards,

Navya.d

  • 0
    TI__Mastermind 23060 points

    Hey Navya,

    I recommend a 4.7kΩ resistor like the datasheet says.  This value matches the recommended value in the TLE75602 datasheet for R_IN.  The DRV81602 is designed to be a drop-in replacement for the Infineon device so you should be able to swap them out without issue. 

    That said, I suspect 100Ω - 5kΩ will all work fine, and 10kΩ might work fine. 

    Best,

    Jacob 

  • 0 in reply to Jacob Thompson
    Prodigy 90 points

    Dear jacob,

    Thanks for the response,let me  try with 4.7k ohm on INX pins.

    1)i want to know is their any pull down on INX pins required to transfer from limp home mode to active mode?

    2)can u let me know what is the rated Power dissipation and calculated power dissipation for IC with load of 250mA MAX.

    Best regards,

    Navya.d

  • 0 in reply to navya diddi
    TI__Mastermind 23060 points

    Hey Navya,

    1. No, see the section below, all that matters is the logic low/high levels

    2. The main losses will be the RDSon losses:  P_RDSon = IRMS^2 x (RDS(ON).  0.250^2 * 0.630Ω = 0.0393 W, or 39.3mW 

    TJ = (PTOT x RθJA) + TA = 0.0393 W * 32.2 °C/W  + 85°C ambient = 86.2°C.  So the device should only warm up by 1.2°C if only 1 channel is on at 250mA.

    I followed the calculations from the DRV8210 datasheet using the DRV81602 numbers:

    Best,

    Jacob

  • 0 in reply to Jacob Thompson
    Prodigy 90 points

    Dear jacob,

    thanks for the calculations,

    -for one channel u r calculating so for 8channels when i consider 0.0393w*8 times as 8channels or only 3HSD channels i should consider as 5 channels are used as LSD in my application.

    -how did you get the 0.630ohms for 250mA?

    Best regards,

    Navya.d

  • 0 in reply to navya diddi
    TI__Genius 13780 points

    Hi Navya.d,

    - Multiplying by 8 should give you a rough estimate. However, total power dissipation depends on many factors. Please see the following app note on more details of power dissipation: Calculating Power Dissipation for a H-Bridge or Half Bridge Driver (Rev. A) Although high-side and low-side switching devices are not exclusively discussed, the same principle applies. 

    - typical RDS(ON) at TJ = 25 °C is 630 mΩ

    Best,

    David