TPS92520-Q1: spread spectrum in this device

The TPS92520-Q1 does not have a spread spectrum feature.  Generally speaking, this device is used in conjunction with a boost converter on the input and the input of the boost converter is where you need to work on input filtering.  For example, the TPS92682-Q1 boost converter does have a spread spectrum feature.  If you aren't using a boost converter in front of the TPS92520-Q1 buck LED driver then you will need to address EMI filtering but making sure the layout is optimized for EMI.  You can also use passive filtering, such as pie filter, to achieve the desired filtering for EMI.  There are other things that you can do such as adding series resistance to the BST capacitor to slow down rising edge of high side FET, but there are some limits to those types of technics because it can adversely affect efficiency or even affect normal operation. 

-Francis Houde

Hello Yuting,

I can't give you an a comprehensive comparison of our device vs other devices because I don't know which parts you are considering using.  I can say some general things about the TPS92520-Q1.  The TPS92520-Q1 is an adaptive on time architecture which means it will switch at constant frequency which means you can tune your input filter.  Most other competitors use Hysteretic devices which changes the frequency to maintain the ripple current which has some pros and cons.  The con is the frequency ranges greatly which depending on the EMI specification you are trying to meet can be a challenge.  The ripple is always the same which is a good thing, but the output capacitor usually address any conducted emission issues easily while EMi is small compared to other aspects of the converter.  EMI failures in BUCK are usually a function of the layout, the rise and fall times of the SW node and the frequencies you are operating compared to the specifications you are trying to meet.   Conducted emissions is usually more easily met with input and output filters.  The bigger challenge will be EMI.  Many competitors don't have monolithic synchronous parts (meaning that both the top side and bottom side FET are integrated into the die), which means the loop areas and amount of exposed switch node is minimized compare to other parts that use external devices like catch diodes or external fets.  This device is unique in that it is designed to used the shielded enclosure as part of the heat sinking, specifically the DAD package.  Because of the power density of this device a good heat sink is needed to operate the TPS92520-Q1 effectively at larger output powers.  If you need a heat sink then you can also use that as shielding.  The automotive industry does this all the time.  Here is a TI Design showing what was done as an example for you.

https://www.ti.com/tool/TIDA-050030 

If you want we can also do schematic and layout reviews of your design.  We generally use Altium, but we can import many other schematic capture and PCB design software file formats.  

Layout will be critical along with other design consideration.  We also need to know which specifications you are trying to meet CISPER? etc?

-Francis Houde