AWR1642: PMIC_CLKOUT signal spec

Hello,
The PMIC_CLKOUT is a divided clock output from the xWR1642. Please note, if the PMIC is initializing, and the xWR1642 is not operating, the PMIC_CLKOUT is NOT a stable clock. So for PMIC startup, if the xWR1642 is not operating, the clock is not available.

I think you have to consider the PMIC operating from an internal clock on startup, and having a method to transfer the clock after the xWR1642 is operating, for special control.

Please tell us more about what you are trying to achieve, if the answer doesn't describe how you are planning to use the devices.

Regards,
Joe Quintal

Here is more detail. We are using the TPS54561 DC/DC as the main supply in our system. We want to sync it to the AR1642 clock to control the spurs. The TPS54561 is sensitive to the output impedance of the driving clock while it is idle during startup, so the circuit we would design is different depending on the startup impedance of PMIC_CLKOUT. Hence we would like to know the electrical spec of this signal (voltage range, impedance during startup, drive capability, etc)

Hello Russell,
The PMIC_CLKOUT is a standard CMOS IO pin from the AWR device . For the electrical characteritics you are look at the section 5.4 of the AWR1642 datasheet. You can also find the switching specs in the table 5-14.
For detailed model you can refer to the IBIS model where you would get the exact IO characteristics (www.ti.com/.../swrm032) . The impedance of the standard IOs is around 50ohms .

Regards,
Vivek

Hi Vivek,

The IBIS model is helpful, thanks. We have v0.85 of the AR1642 datasheet (the one available on "mySecure") and section 5.4 doesn't seem to have the information you describe, and there is no table 5-14. Is there a later version?

Sure, no problem. If you have any further query do let us know.

Thanks and regards,
Vivek