Hi,

I would like to know is there any difference on the placement of the Inductor DCR sensing.

On the datasheet of LTC3784 the DCR sensing the capacitor and resistor is parallel, whereas on the application note 136 using LTC3855 the application note show a different placement of the DCR sensing.

And also I notice on the buck regulator EMC using LTC3891 is the same configuration as the AN136.

Any feedback or comments will be much appreciated.

Thanks in advance.

The DCR sensing is described in detail on page 16 of LTC3784 data sheet. The resistors R1 and R2 along with capacitor C1 in Figure 2B are used to replicate the current sense waveform required for current mode operation. The resistor R2 is not always required. The equation on page 17 can be used to calculate the values of R1, R2 and C1.

I hope that this helps.