I'm currently testing a board using ADV7611 and ADV7513 chips.
The I2C communication with the ADV7513 chips is working but not with the ADV7611 (no acknowledge of the I2C address 0x98 or 0X9A).
So, I have checked everything around the chip:
- chip orientation
- pull-up resistors value on I2C lines
- CAD implementation
- supplies values and stability
- the reset pin is held low during power up sequence
- no I2C access after the reset pin is released
I have an evaluation board to compare my measure and the only difference between my board and the eval board is the power sequence.
The ADV7611 chip need a power up sequence for the 3V3 and 1V8 supplies.
I respect the sequence (1V8 ramp after 3V3 stable) but the 1V8 supply is only establish 180ms after the 3V3 supply is stable (the 1V8 regulator is driven by a voltage monitor).
On the evaluation board this time between the 3V3 and 1V8 ramp is only 12ms.
I didn't find any recommendation on the datasheet or on the UG-180 for this time between the two ramp.
This is a problem to have 180ms between the two supplies ramp? The chip can be blocked if the power up sequence is too long?