Using external capacitor to provide burst current in LMZ10503

Ankit Raj

Other Parts Discussed in Thread: LMZ10503

I am using LMZ10503 voltage regulator in my circuit. My battery provides 1 A at 5 V as input. I can get about 1.4 A at 3.3 V from the voltage regulator. My load requires a current burst of 2 A for 477 usec after every 5 minutes. I am using a big capacitor of 820 uF at the input of the regulator ( calculated value is about 500 uF). I am not using big capacitor near the input of load as it requires very big ( about 9 mF). I am doubtful if it will work. Please help.

over 11 years ago

0 Frank De Stasi over 11 years ago

TI__Guru 72355 points

Such a large Cout would not be a good idea. It may be unstable or not start-up. You could try Webench and see if it is stable. I will pass this along to the apps engineer for this device.

0 Ankit Raj over 11 years ago in reply to Frank De Stasi

Prodigy 70 points

I am thinking of using capacitor of 820 uF at the Vin of the regulator. Calculated value is 500 uF.

The capacitance required is 9 mF if used at Vout of the regulator (near load).

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Using external capacitor to provide burst current in LMZ10503