TPS386000: change TPS386040

GARETH OU

Guru 11365 points

Part Number: TPS386000
Other Parts Discussed in Thread: TPS386040,

Customers originally used TPS386000, need to change TPS386040

Whether to remove the pull-up resistor or any need to adjust ?

over 3 years ago

0 Jesse Villanueva over 3 years ago

TI__Mastermind 18690 points

Hi Gareth,

Thank you for you question. Yes, to switch from TPS386000 to TPS386040, removing the pull up resistors is the only thing they need to do.

Jesse

0 Balaji Appadurai45 over 2 years ago in reply to Jesse Villanueva

Prodigy 210 points

We have replaced TPS386000 with TPS386040 due non availability of TPS386000 in one of old Boards.

If we replace TPS386000 with TPS386040, Why should we removed Pull Up Resistor at Reset Pins?

If Manual Reset is pressed, Without removing Pull up resistor, I expect Reset pin should assert to Low in TPS386040. it is not behaving as expected. How does this Pull Up resistor impact?

0 Jesse Villanueva over 2 years ago in reply to Balaji Appadurai45

TI__Mastermind 18690 points

Hi Balaji,

Since the TPS386040 is a push-pull device, the pull-up resistor on the reset pin is going to be parallel with a pmos making the device less power efficient.

For the MR pin, when the pin is connected to ground it should assert RESET1. Could you please connect the MR pin directly to ground and check if RESET1 assert. Without a pull-up resistor on the MR pin should also assert RESET1 since MR is ANDed with the SENSE1 pin.

Jesse

0 Balaji Appadurai45 over 2 years ago in reply to Jesse Villanueva

Prodigy 210 points

I think there is Miscommunication. I was referring to the pull up resistor on the reset pin. Do this pull up resistor on reset pin of 6040 has any side effect Since we have replaced TPS386000 with TPS386040

0 Jesse Villanueva over 2 years ago in reply to Balaji Appadurai45

TI__Mastermind 18690 points

HI Balaji

Sorry about that, yes the pull-up resistor have will affect the device. From the image you posted above, the inverters connected to the RESET output are CMOS inverter, making the pull-up resistor parallel with the PMOS portion of the inverter. Depending on the value of the pull-up resistor being used, the effect may vary. I would highly recommend removing the pull-up resistor for push-pull devices.

Jesse

0 Balaji Appadurai45 over 2 years ago in reply to Jesse Villanueva

Prodigy 210 points

Pull up resistor value is 10K. Our intention is to have 6040 (Push Pull reset output) as an alternate part in the BOM and In case of non-availability of 6000 (open Drain reset output), 6040 (Push pull) can be used. I was under impression that pull up -10K on reset pin of 6040 should not create any Issue. Do you strongly recommend to remove pull-up R559 & R556 if 6040 is used. Is my understanding Right?

0 Jesse Villanueva over 2 years ago in reply to Balaji Appadurai45

TI__Mastermind 18690 points

Hi Balaji,

Yes, I would highly recommend removing the pull-up resistor on a push-pull device.

Jesse

0 Balaji Appadurai45 over 2 years ago in reply to Jesse Villanueva

Prodigy 210 points

In the schematic I have shared, all reset outputs are shorted. During manual reset, RST#1 will go low but all other RST# will be high in Push-pull device (6040). Can this create an issue in 6040 but not in 6000?

0 Jesse Villanueva over 2 years ago in reply to Balaji Appadurai45

TI__Mastermind 18690 points

Hi Balaji,

Having the RST outputs of the 6040 OR'd will not cause issues.

Jesse

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TPS386000: change TPS386040