DP83867IR: Does power glitch has effect on bootstrap configuration on PHY chip DP83867IRRGZ

jimmy xu1

Part Number: DP83867IR
Other Parts Discussed in Thread: STRIKE

TI PHY chip DP83867IRRGZ is used in our design to interface Xilinx FPGA. We noticed there is a power strike once +5V is supplied to the board, which is the input of power regulator (TPS82085SILR) to output +3.3V (VDDIO). The +3.3V is also used as the input of other two LDOs which output +2.5V (VDDA2P5), and +1.0V (VDD1P0), as shown in following three scope screen shots:

The question is the power strike could have an effect on bootstrap configuration of PHY chip DP83867IRRGZ.

Please advise.

Jimmy

over 5 years ago

0 Cecilia Reyes over 5 years ago

TI__Genius 9920 points

Hi Jimmy,

Can you please clarify to me what you mean by a power strike? And can you explain the situation of each photo?

0 jimmy xu1 over 5 years ago in reply to Cecilia Reyes

Intellectual 490 points

The first scope screen shot is power supply ramping sequence (+5V, +3.3V,+2.5V, and +1.0V). There are voltages (+3.3V, +2.5V, and +1.0V) up on the left .

The second screen shot is the zoom in scope traces on the power up glitch area of the first scope screen shot.

The third screen shot is the zoom in scope trace in the right half area of the first screen shot.

My question is the power strike at the beginning of power up could have an effect on bootstrap configuration of PHY chip DP83867IRRGZ

0 Cecilia Reyes over 5 years ago in reply to jimmy xu1

TI__Genius 9920 points

Hi Jimmy,

I see now. Thank you for clarifying. Can you please share the schematic with the power supplies you are using on this devices?

I'd like to review the components to confirm.

Thanks,

Cecilia

0 jimmy xu1 over 5 years ago in reply to Cecilia Reyes

Intellectual 490 points

Hi Cecilia,

The problem is resolved after the enable pins of 3.3 power regulator is tied to a 3.3V instead of connecting it to +5V before.

Thanks,

Jimmy

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DP83867IR: Does power glitch has effect on bootstrap configuration on PHY chip DP83867IRRGZ