EM7590, EM7565, EM8695 pin 23 and pin 68 voltage tolerance

IoT Modules MC/EM Series
1

Hi

I have questions about two pins of the EM7590/EM7565/EM8695 modules:

1. Pin 23 (WAKE_ON_WAN#) is defined as type open collector OC in the “host interface” table but as type output O in the “module control signals” table. There is no specification about the maximum allowable pullup voltage on this pin, only a pullup to VCC (3.3V) is described in a figure.

Is pin 23 typ OC or O?
Which is the power domain of this pin and maximum voltage allowed at pin 23?

2. Pin 68 (NC) is defined as Reserved in the “host interface” table. The M.2 Key B standard specifies this pin as SUSCLK input with 1.8/3.3V tolerance.

Is it allowed to connect pin 68 to a 3.3V suspend clock oscillator or must it be open (disconnected)?

Thanks for your help.

2

Pin 23 – Open drain output, its output is either floating or pulled low. Pull-up voltage depends on external host.
Pin 68 – It is open and not connect to any internal circuit internally.

it is same comments for all EM7590/EM7565/EM8695 modules

3

Hi jyijyi

Thanks for this information.

You write that the pull-up voltage on pin 23 depends on the external host.
What is the maximum allowable value for this pull-up voltage?
Is it the same value for all EM7590/EM7565/EM8695 modules?
Where do we find this information in the datasheets?

4

there is no standard requirement for the maximum allowable value

5

Hi jyijyi

I doubt that we can put a pull-up to 100V, so there must be an max value for the pull-up voltage, like 3.6V or similar…

6

why don’t you just use VCC as the pull up voltage value?

7

If it is allowed to pull-up to VCC (3.3V nominal), then it is ok. I did not find this information in the “Host interface” table 3-1, where the electrical limits of all signals are listed, that’s why I asked.
Some other manufacturers restrict this pin to 1.8V power domain.

8

i would suggest you just leave it open if you don’t use this pin

9

We want to use the WAKE_ON_WAN# function, so we have to connect pin 23.

10

if your external circuit uses same voltage as VCC, then you can use VCC as the pull up voltage