AN3355

Designing a board compatible with both devices

Doc ID 018544 Rev 2

7/11

Comparing this with the M24LRxxE-R requirements, we can see that:

●

–

OK for the M24LRxx-R,

–

●

–

OK for the M24LRxx-R,

–

●

If pin1 is left unconnected (HiZ):

–

OK for the M24LRxx-R.

–

OK for the M24LRxxE-R.

We can see that the correct way to design an application accepting either M24LRxx-R or

M24LRxxE-R is to define E0=0 for the M24LRxx-R.

Conditions applying to pin7:

The M24LRxx-R pin7 is the E1 input. Its logical value is internally read as:

●

●

●

or E1=0 when left unconnected (HiZ).

Comparing this with the M24LRxxE-R requirements, we can see that, consequently:

●

–

OK for the M24LRxx-R,

–

not compatible with the M24LRxxE-R: this would create a short-circuit when

WIP/Busy outputs a 0.

●

–

OK for the M24LRxx-R,

–

therefore inhibit the WIP/Busy information.

●

If pin7 is left unconnected (HiZ):

–

OK for the M24LRxx-R,

–

OK for the M24LRxxE-R.

Table 1.

Compatibility overview (Pin1)

Pin1

M24LRxxx-R

M24LRxxE-R

Result

E0=1

Conflict on Vout

Not possible

E0=0

Conflict on Vout

Not possible

Left unconnected

(or connected to a

high impedance)

E0=0

OK

OK