TRF372017: Register Setting

Allan Fan

Part Number: TRF372017
Other Parts Discussed in Thread: TRF3722

Team,

We would like to replace ADRF6755 with TRF372017 and want to confirm if it's a good competition. But we don't find below spec information of TRF372017. Do you have any data can share?

In addition, could you please help provide basic setting for output 750Mhz and external VCO = 30.72Mhz for customer evaluation?

Thanks.

over 6 years ago

0 Yusuf%20Agoro over 6 years ago

TI__Expert 4880 points

Hey Allan,

For clarification you would like register settings for an RF out of 720MHz, with a PFD of 30.72M correct?

Also which mode? Fractional or integer?

and to answer your questions....

The following can be found in the TRF372017 data sheet: http://www.ti.com/lit/ds/symlink/trf372017.pdf

In Fractional mode, the feedback divider fractional portion is non-zero on average. With 25-bit fractional resolution, RF stepsize fPFD/2^25 is less than 1 Hz with a fPFD up to 33 MHz; pg 23

Max PFD = 100MHz; pg 6

LO = 300MHz- 4800MHz; pg 7

Yusuf

0 Allan Fan over 6 years ago in reply to Yusuf%20Agoro

TI__Expert 5730 points

Hi Yusuf,
Sorry, to clarify, customer use 30.72MHz TCXO and same 30.72Mhz PDF setting for loop filter as table 30 in datasheet. RFout needs 720Mhz. Integer mode is good.

Could you please generate settings from the GUI?

Thanks.

0 Yusuf%20Agoro over 6 years ago in reply to Allan Fan

TI__Expert 4880 points

Hey Allan,

It seems you are using the recommended loop filter for fractional mode which will work with your desired RF output and PFD. The TRF3722 actually offers better performance for your setup than the TRF3720. That may be the better option. The biggest difference is the common mode voltage required at the baseband I & Q inputs. You would need a 0.25-0.5 Vcm with the 3722 as opposed to a Vcm of about 1.7V with the 3720.

Here are some of the parameter you wanted to compare with competitor as well as the link to the datasheet. If this seems like a better option for the customer and they have no problem with the difference in common mode voltage, let me know and i will send you the desired register settings.

http://www.ti.com/lit/ds/symlink/trf3722.pdf