TDA4VEN-Q1: USB2.0 schematic

Furuna Yamamoto

Part Number: TDA4VEN-Q1

Hi.

[Regarding Request Number E2E1633812]

Please tell me about the circuit diagram of USB0_DRVVBUS.
Of the three resistors in the external circuit, is it possible to change the 16.5 kohm to 16 kohm?
We do not have a usable lineup within the company, and if possible, we would like to make the change.

Regards,

2 months ago

0 ShreyasRao 2 months ago

TI__Guru 63890 points

Furuna,

With the new modification, you will still have 3.3V at the pin which is within the limits of the Vbus operation. 19.5/29.5*5 = 3.3V. You should be fine.

Edit: it is 5v/3 = 1.67 actually. and this change should be fine since you are within the range of USB_Vbus.

0 Furuna Yamamoto 2 months ago

Intellectual 400 points

Hi. Rao-san,

Thank you for your reply.

I apologize for the amateur question, but please teach me.

What is the requirement for the 1.67V (=5V/3=5V/(10k/29.5k)) applied to the VBUS terminal?

Is this a general input specification for the device-side VBUS terminal?

Best regards,

0 ShreyasRao 2 months ago in reply to Furuna Yamamoto

TI__Guru 63890 points

Hi Furuna-san,

The datasheet specifies that the valid range for the USB_VBUS is b/w 0-3.6V(max). As long as it is within that limit, it should be considered valid input.

0 Furuna Yamamoto 2 months ago in reply to ShreyasRao

Intellectual 400 points

Hi Rao-san,

Thank you for your explanation.
I am starting to understand little by little.
Is my understanding below correct?
1) The purpose of the TDA4VEN VBUS terminal is to determine whether the Host is connected.
2) Since the objective is to determine the presence of the Host connection, an input voltage of about 1.67V on USB0_VBUS is fine.

Regarding the above point 2),
3) Where in the datasheet is the input voltage range for the USB0_VBUS terminal (the voltage that recognizes Host connection) described?

Regards,

0 ShreyasRao 2 months ago in reply to Furuna Yamamoto

TI__Guru 63890 points

Furuna-san,

Yes your understanding is correct, Vbus and Vbus detection whenever a device is connected is essential for the operation.

0 Furuna Yamamoto 2 months ago in reply to ShreyasRao

Intellectual 400 points

Hi. Rao-san,

If the input voltage range of the VBUS terminal is 0 to 3.465 V, are the three voltage divider resistors okay with a 10% tolerance?

The typ value for the current constant is 1.67V.

Regards,

Yamamoto

0 ShreyasRao 2 months ago in reply to Furuna Yamamoto

TI__Guru 63890 points

Yamamoto-san,

It seems that the voltage would drop to 1.55V with 10%. Is there restriction on the resistor availability based on the tolerance as well? I would suggest to keep it at 1% as suggested by the datasheet.

0 Furuna Yamamoto 2 months ago in reply to ShreyasRao

Intellectual 400 points

Hi Rao-san,

Excuse me, it seems that I do not understand the datasheet.

"USB0 Level-Shifted VBUS Input" is listed as "0 - 3.465V."

What is the VBUS input voltage level for recognizing that a host is connected to USB0 ch.?

Isn't it from min 0V to max 3.465V?

0 ShreyasRao 2 months ago in reply to Furuna Yamamoto

TI__Guru 63890 points

Yamamoto-san,

Yes, b.w 0V to 3.465V is the valid range. When a device is connected, and the SoC is configured for host mode, then the Vbus is powered through the power switch and powers up the device.

The USB_Vbus needs to be fully powered down to 0V before ramping up again for device attachment.

0 Furuna Yamamoto 2 months ago in reply to ShreyasRao

Intellectual 400 points

Rao-san,

I understand that the valid input range of the VBUS terminal is 0 - 3.465V.
Then, what is the minimum input voltage level at which the SoC recognizes that the Host is connected?

Regards,

0 ShreyasRao 2 months ago in reply to Furuna Yamamoto

TI__Guru 63890 points

Yamaoto-san,

The USB spec mentions that the device must be able to attach within Vbus reaching 4V. below that threshold, it may not be able to properly enumerate or work.