M24C01/M24C02 device addressing restriction

LazarCG · ‎2024-10-30

Hi,

We're developing a PCB that can have multiple different I2C ICs assembled and have chosen the M24C02-RMC6TG EEPROM for board identification.

In the datasheet, section 4.5, a note states no other device using the 1010 xxxx address can be connected to the same bus. The note also begins with "When using the DFN5 package:".

I'm unsure whether this statement applies only for the DFN5 package or in general? (Datasheet snippet below)

One of the intended ICs that we plan to implement can be configured to have either 1010 011 or 1010 010 I2C address. Can this IC be on the same bus with this EEPROM? (With the address configured to not overlap with the other IC)

Thanks in advance,

Lazar

MHoll.2 · ‎2024-10-30

Sorry i dident read your question to the end,

Yes You can use the DFN5 chip with an other Chips having Adress 0x52 or 0x53, the M24C02 uses only 1 Address becase the EEPROM size is 256Byte (2KBit) so the Adress is only in the 2. Byte of the I2C command, not wrapping over into the Adress byte.

View solution in original post

MHoll.2 · ‎2024-10-30

Hi,

the DFN5 package has only 5 pins, so the E0..E2 inputs are fixed to LOW, You are using one of the 8 Pin packages so You have the E0..E2 pins. With this pins You can select up to 8 M24C02 IC's (Address 0x50 to 0x57) there is no overlapping.

LazarCG · ‎2024-10-30

Hi,

Thank you for the quick reply!

I'm still wondering why is this restriction only applicable to the DFN5?

The 8-pin variant can also be configured with E0..E2 low, giving it the 0x50 address which does not overlap with our IC (0x52 or 0x53) and this would be viable?

But the DFN5 has E0..E2 configured low Internally, I assume, and it is not viable to use it even though the addresses do not overlap?

What is the reason behind the restriction of using devices with 1010 xxxx addresses on the same bus, even if there is no overlapping?

Thanks

MHoll.2 · ‎2024-10-30

The DFN5 has only 5 pins, so there are no pin's left for E0 to E2, thats the reason.

The DFN5 chip will always be on Address 0x50, so only one chip in this package is allowed in the same I2C Bus.

MHoll.2 · ‎2024-10-30

Sorry i dident read your question to the end,

Yes You can use the DFN5 chip with an other Chips having Adress 0x52 or 0x53, the M24C02 uses only 1 Address becase the EEPROM size is 256Byte (2KBit) so the Adress is only in the 2. Byte of the I2C command, not wrapping over into the Adress byte.

LazarCG · ‎2024-10-30

No problem.

Thank you so much for your time.

Best regards,

Lazar