TPS40211-Q1: PSpice simulation error

Danilo A.

Mastermind 26260 points

Part Number: TPS40211-Q1
Other Parts Discussed in Thread: PSPICE-FOR-TI, TPS40211

Hi Team,

Our customer wants to design a boost converter from a 10V to 14.4V battery input to 100V@0.5A output.

He tried to simulate the design in Webench as shown below.

12V to 100V Boost TPS40211.pdf

However, when he simulated the same design with same values of components in PSpice-for-TI, he noticed that the device goes to over current state using a 12mOhm shunt resistor. The current at the shunt resistor is 12.5A.

4572.Sch.pdf

The customer's concern is why the device goes to over current condition in PSpice but it is working in Webench. He tried to adjust the shunt value & Css cap to check if it will improve. But it works only when they bypass the over current protection by grounding Isns. Please see the output waveforms below.

What could be the cause of this issue?

Regards,

Danilo

over 1 year ago

0 EM over 1 year ago

TI__Genius 11215 points

Hello,

Thanks for reaching out. We are currently looking into this and will come back to you as soon as possible.

Kind regards,
EM

0 EM over 1 year ago in reply to EM

TI__Genius 11215 points

Hello,

Would it be possible to run this simulation with a lower output capacitance (e.g. half of the current value), lower sense resistor and with lower load? Would it be possible to ask the customer to share the TI PSPICE file with us so that we can take a look? What is the desired switching frequency that the customer would like to have? The design should not be implemented without sense resistor, so we would like to check on our side why the design is entering current limit.

Kind regards,
EM

0 Gaurav Patni over 1 year ago in reply to EM

Prodigy 40 points

Dear EM ,

Please refer attached simulation project based on Webench design .
We tried to change output cap but no success . Even with no load we are not getting 100V with 10V DC input

Note :webench design file is also attached.
Thanks ,
Gaurav

TPS40211_100V_Boost.zip

0407.12V to 100V Boost TPS40211.pdf

0 Stefan Schauer over 1 year ago in reply to Gaurav Patni

TI__Mastermind 47141 points

Hi Gaurav.

i had a look into the design and think the issue is the softstart time which is defined by the softstart cap on SS pin.

In your simulation it is just 820nF which is quite short and as this value is taken from Webench I assume that estimation in Webench was that during startup no additional load is connected and the initial current is just used for charging up the output cap.

But as you have already from the initial startup time the load R8 with 200 Ohm connected, additional current is going into that and therefore triggering the over current limit.

Best regards,

Stefan

0 Gaurav Patni over 1 year ago in reply to Stefan Schauer

Prodigy 40 points

Hi Stefan,

Thanks for your reply.
Based on your suggestion , I simulated the circuit with very high load ( 1M ) and able to get desired 100VDC output .
But could you please suggest suitable why where I can change the load resistance after TPS40211 gets stabilized or say after time t ?

Note : I have raised the query for how to do resistor sweep in pspice

https://e2e.ti.com/support/tools/simulation-hardware-system-design-tools-group/sim-hw-system-design/f/simulation-hardware-system-design-tools-forum/1166771/pspice-for-ti-pspice/4389743#4389743

Thanks ,
Gaurav

0 Stefan Schauer over 1 year ago in reply to Gaurav Patni

TI__Mastermind 47141 points

Hi Gaurav,

i would use a voltage-controlled switch and control this with a signal generator or PWL voltage source.

Best regards,

Stefan

0 Stefan Schauer over 1 year ago in reply to Stefan Schauer

TI__Mastermind 47141 points

Hi Gaurav,

as we have not received an additional information, I assume this issue is solved and I am closing the thread.
If there is still something open, just reply to open it again or open a new thread.

Best regards,
Stefan

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TPS40211-Q1: PSpice simulation error