VBUSCLMP voltage

[pascalpellet]

processor : #T1040 #USB #VBUSCLMP

The Divider  network at VBUS (datasheet §4.5.4.1) shows a voltage divider from 5V (VBUS) to 1.3V (VBUSCLMP)  (resistor divider = 18.1/(18.1+51.1)).

I can't find any explanation for this value. Is there a AN ?

Best regards.

[Pavel]

The Section 5.2 of the USB OTG Specification requires that the input impedance of Vbus should be between 40K to 100K over the 0V to 5.25V Vbus input range.

The T1040 USB if this divider is not used does not provide this requirement.

There is no discrepancy to this requirement if this divider is used.

Have a great day,
Pavel Chubakov

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[pascalpellet]

Hi Pavel :

I find this comment for the P1010:

“The VBUSCLMP circuit power supply is 3.3V. The VBUSCLMP absolute maximum rating is 0.3V to 3.63V.Factory recommends using external divider to reduce the voltage range into 0v to 1.37V.”

Is it the same behavior on T1040 ? so if VBUS=3.3V, do I have to change the resistor divider to have VBUSCLMP between 0 to 1.37V ?

Best regards,

Pascal

De : PELLET,Pascal (INT)

Envoyé : mercredi 29 août 2018 09:37

À : 'jive-1629071468-6z29-2-mj3f@mail.freescale.jiveon.com'

Objet : RE: - Re: VBUSCLMP voltage

Hi Pavel,

Thank you for you your support. This means if VBUS is set to 3.3V, this resistor divider (51.2k – 18.1k) follows the requirement ?

Best regards,

Pascal

De : Pavel

Envoyé : mercredi 29 août 2018 07:24

À : PELLET,Pascal (INT)

Objet : Re: - Re: VBUSCLMP voltage

NXP Community <https://community.freescale.com/resources/statics/1000/35400-NXP-Community-Email-banner-600x75.jpg>

Re: VBUSCLMP voltage

reply from Pavel Chubakov<https://community.nxp.com/people/Pavel?et=watches.email.thread> in T-Series - View the full discussion<https://community.nxp.com/message/1051179?commentID=1051179&et=watches.email.thread#comment-1051179>

[pascalpellet]

Hi Pavel,

Thank you for you your support. This means if VBUS is set to 3.3V, this resistor divider (51.2k – 18.1k) follows the requirement ?

Best regards,

Pascal

De : Pavel

Envoyé : mercredi 29 août 2018 07:24

À : PELLET,Pascal (INT)

Objet : Re: - Re: VBUSCLMP voltage

NXP Community <https://community.freescale.com/resources/statics/1000/35400-NXP-Community-Email-banner-600x75.jpg>

Re: VBUSCLMP voltage

reply from Pavel Chubakov<https://community.nxp.com/people/Pavel?et=watches.email.thread> in T-Series - View the full discussion<https://community.nxp.com/message/1051179?commentID=1051179&et=watches.email.thread#comment-1051179>