LMR14020-Q1: Query regarding the design

Shubham Singhal

Prodigy 95 points

Part Number: LMR14020-Q1
Other Parts Discussed in Thread: LMR14020

We have been developing a design using LMR14020 for:

Vin = 13.5V

Vout = 5 V

Iout = 1A

Please suggest if we could use Electrolytic capacitor instead of Ceramic capacitor as Cout and Cin, also please suggest the possible values for them.

Also suggest some parameters to keep in my mind to gain more efficiency and less EMI

Please revert as soon as possible

over 8 years ago

0 Vincent Zhang(BSR) over 8 years ago

TI__Expert 4795 points

Hi,

Of course you could use Electrolytic cap as Cin and Cout. I would suggest Cin as 47~100uF and Cout less than 220uF considering the cost.

By the way, may I know why you would like to use the E-cap?

To improve efficiency and EMI, I suggest to run at low frequency like 500kHz and to add some EMI filter before the input.

If you need to pass CISPR25 Class5, I suggest below circuit.

0 Shubham Singhal over 8 years ago in reply to Vincent Zhang(BSR)

Prodigy 95 points

Hi Vincent,

Thank you very much for your suggestion , the only reason for using electrolytic cap is the costing of ceramic caps.
And I need to pass following standrds:
CISPR 12
ISO 7637-2
ISO 11451
Please suggest some guidelines related to that.

0 Vincent Zhang(BSR) over 8 years ago in reply to Shubham Singhal

TI__Expert 4795 points

Hi Shubham,

I think you can seatch some automotive TI designs like TIDA00699 on ti.com for reference. Meanwhile, for EMI standards, we usually need to pass CISPR25...

Regards,
Vincent

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LMR14020-Q1: Query regarding the design