TPS61240-Q1: Current limit when simulated in PSPICE-for-TI

Dixit Jones Zachariah1

Part Number: TPS61240-Q1

Hi,

As per TPS61240-Q1: Output Current Limit - Power management forum - Power management - TI E2E support forums, the output current supported is upto 240 mA, but simulation shows that the device is unstable (considerable noise) when tried to drive at 230 mA resistive load. With no load connected, the output looks perfectly OK.

Please guide on what went wrong.

Simulation circuit

The input and output capacitors used 10 uF each while the inductor used is 10 uH.

Simulation result

Kindly help to understand this behavior.

Dixit

over 1 year ago

0 Nini Zhong over 1 year ago

TI__Expert 6015 points

The faxt is that there maybe a little difference between the pspice and bench test due to tiny variation about the loop parameter. Under this case, the pspice maybe a little different from bench test. Recommend you to try then bench test under this condition.

0 Dixit Jones Zachariah1 over 1 year ago in reply to Nini Zhong

Prodigy 80 points

Hi,

Thanks for the response.

In turn, I have tried with a much lesser load of 10 mA (connected a 500 Ohm as load) wherein observed ripple is of 300 mV magnitude.

Interestingly, a frequency of around 500 kHz is also seen along with approx. 3.5 MHz. Can you please let me know if this is expected from this device. I wish to confirm the performance from the simulation before going to bench.

Dixit

0 Nini Zhong over 1 year ago in reply to Dixit Jones Zachariah1

TI__Expert 6015 points

We didn't run into this phenomenon in bench test. It's not expected from the device.

0 Dixit Jones Zachariah1 over 1 year ago in reply to Nini Zhong

Prodigy 80 points

Hi,

Thank you so much.

I understand that the ripple observed has something to do with model/ tool.

Dixit