UCC28065: Three channel Interleaved CCM solution vs FAN9673Q

Hello Marc, 

The UCC28070A 2-channel interleaved CCM PFC controller is the best alternative to the FAN9673Q device.  
We do not have a 3-channel analog controller, although one can be constructed using a digital controller such as the C2000 MCU (ref: https://www.ti.com/tool/PMP40690 ).

The UCC28065 that you reference in the E2E title is a 2-channel interleaved Transition-Mode PFC controller.  It does not operate in CCM. 

3 channels of interleaving does not necessarily provide a great advantage over 2 interleaved channels.  Mostly, it disperses the losses more widely and reduces component volume somewhat at the expense of higher BOM count and costs.   
This white paper:  https://www.ti.com/lit/pdf/slua746 shows in Figure 10 that 2 channel interleaving provides 100% cancellation (0% ripple) when the duty cycle is 50% which is where the current ripple peak-to-peak magnitude is highest.  3-channel interleaving provides 100% cancellation at ~0.33 and ~0.66 duty, but the actual  ΔI at those points are already lower.  And it only cancels about 70% at the highest ΔI at duty = 0.5.  

Also the UCC part is less than 1/2 the cost of the FAN device, while retaining most of the basic functions.
And two UCC28070 controllers can be easily paralleled to provide 4-phase interleaving, if desired, which retains 100% ripple cancellation at max ΔI as well as lower remaining ripple. 

Regards,
Ulrich