CDCE913: Modulation Frequency

NAOKI AOYAMA

Guru 11215 points

Part Number: CDCE913

Hello,

Our customer use the CDCE913.

The using configuration of the customer as follows.

Input frequency : 50MHz

Output frequency : 166MHz

SSCG : center spread +/- 0.5%

How about the modulation frequency of the SSCG?

Best Regards,

Naoki Aoyama

over 7 years ago

0 Simon Damphousse over 7 years ago

TI__Expert 5370 points

Dear Aoyama,

The SS modulation shape is triangular and is fixed. It is not possible to generate other shapes.
The modulation frequency is related to VCO frequency and D/S report to be higher than 20 kHz.

Best regards,
Simon.

0 NAOKI AOYAMA over 7 years ago in reply to Simon Damphousse

Guru 11215 points

Hello Simon,

Thank you for your reply.
The customer want to set the modulation frequency as 30kHz - 33kHz.
What the frequency of the VCO should the customer set?

Regards,
Naoki Aoyama

0 Patrick Kammermayer over 7 years ago in reply to NAOKI AOYAMA

TI__Expert 5325 points

Hello Aoyama-san,
when you want to have 166 MHz output, you only have the option to run VCO at 166 MHz.
When you use VCO1_0_RANGE (or VCO1_1_RANGE) bit field you can adjust the SSC modulation rate. When the selected range fits to the actual VCO frequency you will get a frequency fairly close to 30-33 kHz.
In your specific case it is slightly higher than 33 kHz for VCO1_0_RANGE=2 . When you select VCO1_0_RANGE=3 (>=175 MHz) you will get slightly under 30 kHz.

Best regards,
Patrick

0 NAOKI AOYAMA over 7 years ago in reply to Patrick Kammermayer

Guru 11215 points

Hello Patrick,

Thank you for your reply.
I see.
I will feedback the customer this information.

Thanks,
Naoki Aoyama

Clock & timing

Clock & timing forum

CDCE913: Modulation Frequency