TPS56C215: TPS56C215

Hi Haim,

This device is not designed for low noise application. So we didn't have detailed evaluation for it now. But first I want to understand which is the (U7 page#2) requirements for EyeQ4 1V. I didn't find the word "U7" in the attached files.

Thanks,

Andrew

Hi Andrew,

Thank you.

U7 is the ref. des. of TPS56C215.

Please see attached.ME8_PS_only.pdf

Hi Andrew,

What is the difference between FCCM and DCM modes ?

Thanks,

Haim G.

Hi Haim,

When there's large load current (load current larger than half of the peak to peak value of inductor ripple current) for the device, there's no difference for DCM and FCCM mode. The difference is only when there's light load for device. 

DCM mode doesn't allow the negative inductor current, so when the load current is smaller than half of the peak to peak value of inductor ripple current, the device will enter discontinuous mode. Switching frequency will become lower with light load and that can help to increase the efficiency at light load. But the output voltage ripple will also increase at light load. 

FCCM mode allows the negative inductor current, so it could keep same switching frequency from light load to heavy load. The output voltage is almost same with changing load, but the efficiency at light load will be worse than DCM mode.

About the requirement for TPS56C215 that you mentioned, if my understanding is correct, is that referred to the Table4 or Table 5 in the EyeQ4 SOC digital core power rail documents?

And which one is the requirements for the U7 power rail? Table 4 or Table 5? Is there any other requirements not mentioned in this table?

Thanks,

Andrew

Hi Andrew,

Thanks for the detailed answer.

Please refer to table 4.

Haim G.

Hi Andrew,

Another question:

What is the max. ripple for DCM and FCCM for the table 4 EyeQ4H requirements ?

Thanks,

Haim G.