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TAS5751MEVM: TAS5751EVM:The SDA and SCL of I2C may be pulled down for a short time when power is on

Part Number: TAS5751MEVM

Hi expert,

When my customer test TAS5751EVM,pull RST and PDN pins low, external power supply 3.3V. Find that whether the SDA and SCL of I2C will be pulled down for a short time when power is on. To be precise, it will appear at the first power-on of continuous power-on and power-off.  When SDA drops, the 3.3V, SCL and SDA waveforms all oscillate. The specific waveforms are shown in Figure 1.

The 4-channel waveform is the current supplied by 3.3V to the EVM.
I use TPS54202EVM to output 3.3V, TPS54202EVM uses 8V power supply, and when TAS5751EVM is not connected, the 3.3V waveform rises smoothly.
Because there are two TAS5751s on the TAS5751EVM, I removed one for testing, and found that the SDA dropped once. Comparing the waveforms with both chips on the top, it seems that each chip will cause an oscillation and cause the SDA to drop once, but the trigger time is slightly different. Please check the attached file for specific comparison waveforms.
Please help analyze why this happens.

Best Regards,

Andy Liu │TI Analog FAE

Mobile: +86-18817878409