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Posts: 1
Registered: ‎06-21-2017

Si1153-AA-09-GMR Sporadic I2C Lockup

[ Edited ]

Hi all,

 

I am currently investigating a hardware issue with one of our design product that uses the Si1153-AA-09-GMR proximity sensor. The issue we encountered is that on some occasions between power cycles the proximity sensor will permanently stop responding to any I2C commands. In this state the only way to recover is to fully remove power from the system and ensure that the voltages on the proximity sensor are discharged to 0V. (We also have a voltage rail issue where the rail retains 0.9V when power is removed, we deemed this to not be the cause but something to consider).

 

I have checked that the LED2 voltage is correctly pulled up on startup and also attempt to talk to the sensor with the alternate I2C address (0x52). From inspecting the I2C waveforms the SDA and SCL lines are not held down by the sensor and is fully functional in talking to other I2C peripherals during this issue.

 

I have also confirmed that LED3 is correctly pulled up on startup. Can anyone shed some light on this issue?

 

Cheers

 

KevinProximity Sensor Circuit

Posts: 58
Registered: ‎04-09-2015

Re: Si1153-AA-09-GMR Sporadic I2C Lockup

Hi Kevin,

 

This is a known issue. The internal voltage monitor is disabled and won't work properly to reset the part when the supply voltage didn't drop low enough. Even though we specified a maximum 1V OFF voltage in the datasheet, it actually has to go below 0.5V to be safe.

 

Regards,

Tony

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Posts: 58
Registered: ‎04-09-2015

Re: Si1153-AA-09-GMR Sporadic I2C Lockup

Hi Kevin,

 

You have also submitted a support ticket in our customer portal regarding the same issue. Please follow up there if you have further questions.

 

Regards,

Tony