EEPROM content erased - M24M01-RMN6P

[HW001]

Hi,

Currently, I am using EEPROM (p/n:M24M01-RMN6P) for data logging.The chip is operating at 3.3V and the circuit shown in the figure below.

An incident happened that the EEPROM content has been erased and when we read back the contents of the EEPROM, the values are all OxFF.

1) Any design error in the EEPROM circut?

2) What are the possible causes that the EEPROM could have been ereased?

3) under what test conditions that it will happen?

4) How to prevent the same incident happen again?

5) What is the maximum ambient temperature that an EEPROM can operate reliably at?

Thanks and regards,

[Peter BENSCH]

Welcome @HW001, to the community!

1. You didn't attach or insert any schematics, so no statement possible yet.
2. Write errors
3. Currently not applicable
4. Check software and timing and avoid write issues
5. The M24M01-RMN6P is specified and guaranteed to operate at an ambient operating temperature range of -40...+85DEGC

Please note that the M24M01-RMN6P is already on NRND (Not Recommended for New Designs).

Regards
/Peter

[Tesla DeLorean]

Excessive heat.

Out of spec voltage when operating on other areas of the memory.

[HW001]

Hi Peter,

Oops,... Please see I2C EEPROM circuitry attached.

[Peter BENSCH]

I cannot recognise any issue from the schematics, but no data loss problems due to such errors are conceivable.

Instead, you should concentrate on the causes mentioned by @Tesla DeLorean and myself.

[Andrew Neil]

So what else is on that I2C bus?

[SofLit]

What if you pull WC\ pin up?:

Do you get the same behavior?

[HW001]

Hi Andrew,

Each I2C bus in the circuit has a coupling capacitor linked to it, but the capacitors were not populated on the board.

Thanks and regards,

[HW001]

Hi SofLit,

I didn't attempt to pull the WC signal too high because the PCB trace is embedded and the signal is connected to ground in the circuit.

Thanks and regards,

[Tesla DeLorean]

Well the idea for -WC is that you ONLY pull it LOW *WHEN* you want to write/erase the content,as a means of protecting it when you're not actually ready to write to it, or conditions aren't suitable.

Does the EEPROM fail in situations when you have no writing code