TPS65265: Schematic review

Hi Muralidharan

Here are my comments:

1. L9 is 6.8uH right? But according my calculation if  LIR = 0.2, L9 should be 3.3uH since your frequency is 1MHz.

2. The load current changes to 2A for CH3? I remember it was 1A before. If the load current is 2A, the saturated current of the inductor should be higher, not  1.6A.

3. I find the saturated current for L8 is 3.6A right? This is a little bit small for a 3A max load. I would like to choose the inductor with saturated of over 4A . If you concern about the size of the inductor, you may choose LIR = 0.3 or larger.

BR

Ruby

Hi Ruby,

1. Vin = 5V, Vout = 1.8V, LIR = 0.2, FSW = 1*10^6 Hz, Io = 1A

L9 = (5-1.8)/(1*0.2) * (1.8/(5*1*10^6)) = 5.76uH 

I chose 6.8uH since that's the closest I could find with the size I am looking for which supports the suitable Ipeak/Isat values.

Hope it is fine to use 6.8uH in that case.

2. Sorry that's a typo. Ch3 is still 1.8V/1A load current

3. I will check on this..

Thanks

Hi Muralidharan

Thanks for your feedback! When choosing inductor, please use the max current of the channel shown in the datasheet. In this case, although your actual load current is 1A, when choosing the inductor, use 2A to do the calculation. So I would recommend to use a 3.3uH inductor.

BR

Ruby

Hi Ruby, 

PFA 

I have changed the inductors L8, L9 as per your suggestions.

Please let me know if this is fine.

Thanks!S0001769A_3buck_20210305.pdf