1. examination of TUSB9261 recognition error additional test

2. Using TUSB9261DEMO power supply
Customer’s board
By using power supply of TUSB9261DEMO in parallel,
In this case, the error happened.

3. Power up sequence and waveform by using TUSB9261 Demo Board
25MHz
40MHz
Lot No.
42WG4C1F9
4AWG4AQ5S
customer board
OK(0/200)
OK(0/100)
ERROR(4/5000)
TUSB9261 Demo Board OK
previous test
Additional test

4. The test of customer’s board
By using customer’s power supply in parallel, both board caused a error.

5. Power up sequence and waveform by using power supply of customer’s board.
25MHz
40MHz
customer board
ERROR
(2/100)
(1/100)
TUSB9261 Demo Board
(2/39)
---

6. In result, the error rate at 40MHz is improved than before.
Power up sequence and waveform by using customer’s board and changed 3.3V power up timing.
He made 3.3V of the customer’s board power up timing faster, simultaneous with 1.1V.
In result, the error rate at 40MHz is improved than before.
25MHz
40MHz
Lot No.
42WG4C1F9
42WG4AP5L
4AWG4AQ5S
customer board
ERROR
(2/66)
(9/1000)
(7/1000)
ERROR(57/1000)

7. Customer’s board by changing VDD11 power up time
When VDD11 power up time is faster, recognition rate was quite improved.
But it couldn’t be zero.
25MHz
Lot No.
42WG4 C1F9
customer board
ERROR
(1/5000)

8. The customer’s question
When VDD11 rising time is faster, error rate is quite improved. What reasons are considered?
Based on the results, it may be caused the slight difference at the start of the power supply. How do you think of it?
According to the datasheet and errata, VDD11 needs to be rising up faster or simultaneously, what is the point starting point of rising or certain voltage. In this case, could you provide what is the voltage.
The timing of DEMO Board, VDD11 is rising when VDD33 is rising, is there any problem?