UCC28C45: UCC28C45:

Satheeshkumar Selvaraj

Part Number: UCC28C45
Other Parts Discussed in Thread: UC1845A, UCC28C42, UCC28C41, UC3845A, UC3845, LM5104

Hi Export,

We are trying to test the working of the Pspice model of UCC28C45in TINA for which we build the open loop laboratory test fixture of UC1845A (as the part is UCC28C45 and UC1845A seemed to be almost same electrically) in TINA but we are not getting anything as simulation. It’s showing convergence problem in details it’s showing component T1.

We tried the same configuration what is below suggested over there but still throwing the same convergence error. https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/904403/ucc28c45-q1-convergence-problem-in-tina?tisearch=e2e-sitesearch&keymatch=convergence%2525252520problem#

Could you please help me.

Thanks,

S.Satheesh

over 3 years ago

0 Steven Mappus1 over 3 years ago

TI__Mastermind 24915 points

Hi,

Thanks for connecting through E2E. Attached is a working model I've used to test open loop operation of UCC28C42...no convergence errors. If you want to import a PSPICE Netlist into TINA, SLVA527 provides instructions how to do this and if you are seeing convergence errors, please make sure all energy storage elements (caps, inductors) have initial conditions applied.

UCC28C42_VMC_Open Loop_Modified_Low CS Imp.TSC

Steve

0 Satheeshkumar Selvaraj over 3 years ago in reply to Steven Mappus1

Prodigy 95 points

The model is working fine but in my circuit we are using UC1845AMDWREP as buck convertor topology ,Whatever you shared model is supported(UCC28C42)only Fly back topology so could you please share me UC1845AMDWREP TINA design simulation file.

Thanks,

S.Satheesh

0 Steven Mappus1 over 3 years ago in reply to Satheeshkumar Selvaraj

TI__Mastermind 24915 points

Hi,

TI does not have a TINA model for UC1845A. You see in the UC3845 and UC3845A product folders, we offer a UCC28C45 PSPICE model only. I offered you a UCC28C42 TINA model which is close to UCC28C45 but differing only by UVLO level and 100% vs 50% max duty cycle. UCC28C41 also has several TINA models available and is 50% duty cycle limited, like UCC28C45 but the UVLO is 7V/6.6V compared to 8.4V/7.6V. Also, if any of these working TINA models are ok for your evaluation, you should be able to reconfigure the topology from flyback to buck.

Regards,

Steve M

0 Satheeshkumar Selvaraj over 3 years ago in reply to Steven Mappus1

Prodigy 95 points

Hi Steven,

Thanks for you input i am try to simulate buck converter using nmosfet circuit.but am not getting output.

Vin-120V;Vout -15V,Fsw-189Khz and Iout max is 2A

Could you please help me below

1.Is this circuit need bootstrap capacitor?

2.UC1845A inbuild driver is available?

3.I need Nmosfet buck convertor reference design.

Thanks,

S.Satheesh

0 Steven Mappus1 over 3 years ago in reply to Satheeshkumar Selvaraj

TI__Mastermind 24915 points

Hi,

The driver stage is ground referenced and you want to drive a high-side N-channel MOSFET. You need to level shift the gate drive to be able to drive the high-side MOSFET. Check out Fundamentals of MOSFET and IGBT Gate Driver Circuits, beginning in section 5, for some good examples of high-side, level shifted gate drive techniques. Here is the parametric filtered list of TI high-side, single-channel, isolated MOSFET drivers, suitable for driving an N-channel MOSFET in a buck converter. Another option could be to develop a level shifted drive suitable for a P-channel MOSFET?

Regards,

Steve M

0 Satheeshkumar Selvaraj over 3 years ago in reply to Steven Mappus1

Prodigy 95 points

Hi Steven,

Thanks for your input.

In my PWM controller i added the LM5104 driver IC to driving the N-Channel MOSFET but am not getting the output.

Vin-10V

Vout-5V

Fw-200Khz

For your reference i attached the TINA simulation File.

Could you please help me.

Thanks,

S.Satheesh

/cfs-file/__key/communityserver-discussions-components-files/196/10V-to-5V-Converter_5F00_3.TSC

0 Satheeshkumar Selvaraj over 3 years ago in reply to Satheeshkumar Selvaraj

Prodigy 95 points

Hi Expert,

The circuit (120V to 24V) supplied by(TL2842BDR-8) TI is built in this schematic. UCC28C42 SPICE model is used here. But we are unable to make this simulation running. We understand that this device accepts only 20V max Vdd but the regulation output is 24V. We tried to separately source this device with a separate power supply. Even after we tried to play around multiple things, we couldn’t make it working. Could you please help me to solve this issue it's very helpful for our design.

Note:For your reference i have attached the simulation file

/cfs-file/__key/communityserver-discussions-components-files/196/120V-to-24V-Converter_5F00_16062021_5F00_TI.TSC

Thanks,

S.Satheesh

0 Steven Mappus1 over 3 years ago in reply to Satheeshkumar Selvaraj

TI__Mastermind 24915 points

A few things I see with your sim are:

Can't have 16V PWM input when the driver is biased with 10V
Current sense is incorrect. Either sense differentially in the position where the 500 ohm resistor is or sense in the low-side SR MOSFER source leg.
Output capacitance is too low

Check your compensation and power stage parameters using TI Power Stage Designer.

Regards,

Steve M

0 Satheeshkumar Selvaraj over 3 years ago in reply to Satheeshkumar Selvaraj

Prodigy 95 points

Could you please help this problem?

0 Steven Mappus1 over 3 years ago in reply to Satheeshkumar Selvaraj

TI__Mastermind 24915 points

I am available to help advise through technical issues but I cannot make the design for you. Have you implemented the changes/recommendations from my previous reply and how did that work? Were you able to run the Powerstage Designer and understand the compensation and finalize the power stage design?

Regards,

Steve M

0 Satheeshkumar Selvaraj over 3 years ago in reply to Steven Mappus1

Prodigy 95 points

Hi Steven,

1.I tried with your suggestion in TINA simulation it's working but some turning is required. Please see the attached simulation output.

2.Currently am interested in simulating the TI reference design based on TL2842BDR-8 kindly help on this.

Thanks,

S.Satheesh

0 Steven Mappus1 over 3 years ago in reply to Satheeshkumar Selvaraj

TI__Mastermind 24915 points

I'm glad you have the simulation working and are able to make changes and see the model behaving as expected. This thread is getting long and moving into another topic so I am going to close it as resolved. Please open a new E2E thread if help is needed. Thanks for connecting through E2E and good luck with your design.

Regards,

Steve

Power management

Power management forum

UCC28C45: UCC28C45: