TUSB4020BI: Pin35/36 set up

Hailiang Zhang

Part Number: TUSB4020BI
Other Parts Discussed in Thread: TUSB4041I

Hi Team，

Could you please comment on how to configure PIN35 and PIN36 of TUSB4020BI? The customer's requirements are as follow.
1. The system provides 3.3V and 1.1V to this device;
2. The upstream of the device is connected to the USB2.0 port, one of the downstream ports is connected to eUSB (similar to SSD), and the other is connected to a USB2.0 Type A.
3. Host can access TUSB4020BI through I2C, and the device is configured as SMBbus mode (1000 101);
4. The USB2.0 Type A interface has an eFUSE

Regards，
Hailiang

over 1 year ago

0 Brian Zhou over 1 year ago

TI__Guru** 123205 points

Both pin 35/36 need to be PD.

what do you mean for item 4?

Regards

Brian

0 Hailiang Zhang over 1 year ago in reply to Brian Zhou

TI__Expert 6585 points

Hi Brian，

Could you please help explain why both pin 35/36 need to be PD? The address for the SMBus doesn't seem to be correct if it pulls down.

Regards，
Hailiang

0 Brian Zhou over 1 year ago in reply to Hailiang Zhang

TI__Guru** 123205 points

pin 35 is PD when the hub support power switch. If not support, then don't need to PD.

when both pins pulldown, address should be 44, it's not tight?

Regards

Brian

0 Hailiang Zhang over 1 year ago in reply to Brian Zhou

TI__Expert 6585 points

Hi Brian，

Hailiang Zhang said:
3. Host can access TUSB4020BI through I2C, and the device is configured as SMBbus mode (1000 101);

Can Pin35/36 be pulled down if the expected address is 1000 101x?

Regards,

Hailiang

0 Brian Zhou over 1 year ago in reply to Hailiang Zhang

TI__Guru** 123205 points

The TUSB4041I device slave address is 1000 1xyz, where:

• x is the state of GANGED/SMBA2/HS_UP pin at reset

• y is the state of FULLPWRMGMTz/SMBA1 pin at reset

• z is the read-write (R/W) bit; 1 = read access, 0 = write access

so 1000 101 means is high. which address is 0x45.

for 0x44 it didn't work?

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TUSB4020BI: Pin35/36 set up