TPS61194-Q1: input inductor current has ring phenomenon

海兵张

Prodigy 40 points

Part Number: TPS61194-Q1

Hi，there has a test waveform，and i can't ensure that whether is ok？

test condition & setup: freq=635KHz, L=33uH; PWM=100%;

input: 13.5V; output current: 180mA;

1. can you tell me why has ring phenomenon for through input inductor current?

2. how much effect for system.such as stability, EMI,etc.

3. how to weaken it.

over 6 years ago

0 Shirley He over 6 years ago

TI__Expert 5475 points

Hi,

It's normal to see some ringing in the inductor current. But the ringing is indeed quite large in the waveform above. It's usually caused by the parasitic capacitor and inductance in the circuit, or the bad layout. It may have some effect on the EMI performance. What is the frequency you measured in the second picture?

0 海兵张 over 6 years ago in reply to Shirley He

Prodigy 40 points

the frequency is about 96MHz, what solutions for the current PCB &inductor

0 Shirley He over 6 years ago in reply to 海兵张

TI__Expert 5475 points

Hi Hobson,

For the layout, please make sure to keep the current loop area as small as possible. GND plane needs to be intact under the high current boost traces to provide shortest possible return path and smallest possible current loops for high frequencies.

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TPS61194-Q1: input inductor current has ring phenomenon