AWR1642BOOST: CLK P and CLK M Pins for External Clock Signal.

George Denove

Part Number: AWR1642BOOST
Other Parts Discussed in Thread: AWR1642, DCA1000EVM,

Hi,

I have 3 AWR1642s connected in a network. They are hardware synchronized (time), but I am looking to synchronize their internal clocks (frequency) with an external 40 MHz signal.

I cannot find where in either J5 or J6 to input both this 40 MHz signal (CLK P pin) as well as the ground signal (CLK M pin) in the AWR1642. Additionally, I have a TI DCA1000 connected to the AWR1642 so I cannot use the J1 pin connectors.

Below is the chart of J5 and J6 options to input the signals:

Thank you!

George

over 5 years ago

0 Cesar over 5 years ago

TI__Guru*** 149104 points

Hi,

Our Hardware team will get back to you

thank you

Cesar

0 aozer over 5 years ago

TI__Mastermind 30755 points

Hello George,

There is no provision on the EVM for an external 40MHz source. You would need to remove the crystal and solder the input directly onto the CLK_P pad of the crystal and then solder the CLK_M pad to GND.

Regards,

Adrian

0 George Denove over 5 years ago in reply to aozer

Expert 1435 points

Hi Adrian,

Thank you for your reply. I do not want to input the 40MHz signal on the DCA1000EVM. I want to input it on the AWR1642BOOST, as discussed and documented in the attached file (specifically the second attached page). You all mention to input it into the CLK_P and CLK_M pin. Where are those on the AWR1642BOOST? Can I use the J5 and J6 pin options as shown above in my first post?

Thanks,

George

4666.TI External Clock Documentation.pdf

0 aozer over 5 years ago in reply to George Denove

TI__Mastermind 30755 points

Hello,

No, the CLK P and CLK M pins are not brought out to any connectors on the EVM. You need to remove the crystal in order to access these pins, they are directly connected to the 40MHz crystal on the EVM. They are not connected anywhere else. You can find the schematics for the EVM on the EVM product page under the design files section which will show the connection of the CLK P and CLK M pins.

http://www.ti.com/tool/AWR1642BOOST#technicaldocuments

Regards,

Adrian

0 George Denove over 5 years ago in reply to aozer

Expert 1435 points

Hi Adrian,

Thank you very much for getting back to me!

To confirm I have this correct, I have attached some pictures for your viewing below. So I would remove the crystal on the front of the EVM. That is denoted by Y1, correct? Then, the CLK P pin is denoted by C15, correct? Then, I would solder the ground signal to C9, correct?

Do you recommend frequency synchronizing 3 distributed AWR1642s any other way than what we are working on here or is this the only way you see fit? I trust your technical background on the AWR more than mine. I just do not want to ruin the function of the AWR by removing the crystal.

Thank you again for all your help!

George

0 George Denove over 5 years ago in reply to George Denove

Expert 1435 points

Hi Adrian,

I hope all is well. I am just circling back around on this. Thanks!

George

0 aozer over 5 years ago in reply to George Denove

TI__Mastermind 30755 points

Hello George,

Yes, you are correct. You should also remove the load capacitors. There isn't really any other way you could sync the 40MHz between multiple EVMs.

Make sure that you clock source meets the specs provided in Table 5-6 of the datasheet.

Regards,

Adrian

0 George Denove over 5 years ago in reply to aozer

Expert 1435 points

Adrian,

Great, thank you for your confirmation! Sounds good about meeting the specs provided in Table 5-6 of the data sheet.

Can you confirm on the exact letter/number associated with the load capacitors I should remove?

Thanks again!

0 aozer over 5 years ago in reply to George Denove

TI__Mastermind 30755 points

Hello,

You would remove C9 and C15 and then you can solder a short across C9 to short the CLK_M pin to GND.

Regards,

Adrian

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AWR1642BOOST: CLK P and CLK M Pins for External Clock Signal.