Dear team,
Is it possible to use higher inductance than 2.2uH for TPS62903 to convert 12V input to 3.3V 0.15A output?
Thanks.
Kind regards,
Aida
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Dear team,
Is it possible to use higher inductance than 2.2uH for TPS62903 to convert 12V input to 3.3V 0.15A output?
Thanks.
Kind regards,
Aida
Hi Aida,
Selecting the inductor is dependent on inductor ripple, output ripple voltage, PWM-PFM transition points, saturation current, DCR and efficiency. The values recommended are in section 8.2.2.4 of the datasheet.
It is possible to use higher inductance to reduce the current ripple, but it will have a negative impact on efficiency and transient response. At low output current in forced PWM mode, larger negative inductor current peaks can happen and exceed the current limits. You can also find more details on LC filter vs Efficiency here.
Regards,
Akshat
Hi Akshat,
Thanks for quick response. In recommended literature TPS62903 is not mentioned. It says only TPS621x0.
Can you please confirm if it is same for TPS62903? Can 10uH coil be used for low ripple current?
Thanks,
Aida
Hi Aida,
I had a follow up question. Are you looking to use a bigger inductor to reduce the ripple current? If so, I would recommend using the 1-2.2uH inductor suggested in the datasheet and add another 22uF output capacitor to reduce the ripple on Vout. This way the ripple is reduced while also maintaining efficiency and space.
Regards,
Akshat
Hi Akshat,
Yes, a bigger inductor to reduce the ripple current. These are requirements: Uin 12V, Uout 3V3, Iout 0.150mA, 1MHz
And TI online calculator gives a coil 5A if 2.2uH. Not able to put 5A coil for 0.15A.
Can you please advise?
Thanks,
Aida
Hi Aida,
Thank you for explaining. I would suggest using our WEBENCH tool to create the build. It will be located in the Design Tools and Simulation section. I was able to use your requirements and create a BOM with a 1uH inductor. Let me know if this works!
Regards,
Akshat
Hi Akshat,
Thanks for your help with WEBENCH. Can you please check the current rate of the coil that it gives? I believe it gives 5A coil, which is not a good solution for my case. In this case, can 10uH coil be used?
Hi Aida,
Yes, it does give a 5.5A rated inductor. You can go ahead and use a 10uH coil. May I ask why the 5.5A coil will not work? There could be another application solution to help with that.
Regards,
Akshat