Hi,

In table 8 of AD9915 datasheet, recommended values of charge pump currents of some N ranges is indicated but for values of N greater than 100, there is not any recommended value. What is the charge pump recommended value for N greater than 100?

Hi,

In table 8 of AD9915 datasheet, recommended values of charge pump currents of some N ranges is indicated but for values of N greater than 100, there is not any recommended value. What is the charge pump recommended value for N greater than 100?

Not that it's useless but it is rare to use those values. After all, the VCO frequency range is at 2.4 to 2.5 GHz. The crystals that are typically used are within 10 to 30 MHz which requires a multiplier of N = 120 (or 2N = 240). Well it depends on the application, In your case, will you be needing a very high multiplication factor?

Best Regards

Louijie

Hi Sahar,

The charge pump current is controlled by using 3 bits data. At N divider with value of up to 100, the recommended current is 1000 uA which is already the full scale current (CFR3[5:3] = 111) of the charge pump. I haven't tried it yet but since it could not go beyond 1000 uA, I recommend to use that value instead.

Best Regards

Louijie