New Christophe Basso SMPS Models

Christophe Basso is writing a new book preliminarily entitled, "Switched-Mode Power Supply SPICE Simulation Cookbook", in which he describes many interesting and useful models, formulas, and circuits that deal with switched-mode power supplies. All of these were crafted by Christophe or translated from earlier models. The models and their demonstration circuits have been ported to MC6 and will soon be a part of the MC6 package. Both the models and some thirty circuits which demonstrate their use are included. Switched Models: Suitable for transient analysis: PWMCM: PWM Current Mode Generic Controller PWMVM: PWM Voltage Mode Generic Controller PUSH_CM: PWM Current Mode Push-Pull Controller PUSH_VM: PWM Voltage Mode Push-Pull Controller HALF_CM: PWM Current Mode Half-Bridge Controller HALF_VM: PWM Voltage Mode Half-Bridge Controller FULL_CM: PWM Current Mode Full-Bridge Controller FULL_VM: PWM Voltage Mode Full-Bridge Controller 2SWITCHCM: PWM Current Mode Two-Switch Controller DEADTIME: Basso Deadtime Generator DEADSYNC: Basso Deadtime Synchronizer DEADDRV: Basso Deadtime Averaged Models: Suitable for AC analysis (and some transient analysis) PWMCCM: Generic Converter Operating in CCM PWMDCM: Generic Converter Operating in DCM BOOSTDCM: Generic Boost Converter Operating in CCM BOOSTCCM: Generic Boost Converter Operating in DCM BUCKCCM: Generic Buck Converter Operating in CCM BUCKDCM: Generic Buck Converter Operating in DCM FLYBACKCCM: Ridley Flyback Converter Operating in CCM FLYBACKDCM: Ridley Flyback Converter Operating in DCM FWDCCM: Ridley Forward Converter Operating in CCM FWDDCM: Ridley Forward Converter Operating in DCM FLYBACKVM: Ben-Yaakov GSIM Flyback Voltage Mode Converter FLYBACKCM: Ben-Yaakov GSIM Flyback Current Mode Converter BUCKVM: Ben-Yaakov GSIM Buck Voltage Mode Converter BUCKCM: Ben-Yaakov GSIM Buck Current Mode Converter FORWARDVM: Ben-Yaakov GSIM Forward Voltage Mode Converter FORWARDCM: Ben-Yaakov GSIM Forward Current Mode Converter BOOSTVM: Ben-Yaakov GSIM Boost Voltage Mode Converter BOOSTCM: Ben-Yaakov GSIM Boost Current Mode Converter SEPICVM: Basso Single Ended Primary Inductance Converter (Voltage Mode) SEPICCM: Basso Single Ended Primary Inductance Converter (Current Mode) SERPA: Basso Series Parallel Model SERIPA: Basso Series Parallel Model Here is the list of sample circuit files that demonstrate averaged (AC) and switched (Transient Analysis) simulations. Demonstrating Averaged Models: A_BUCK_CM.CIR A_BUCK_VM.CIR A_SEPIC.CIR A_BOOST_CM_OL.CIR A_BOOST_CM_ZOUT.CIR A_BOOST_VM.CIR A_BUCKBOOST.CIR A_FLYBACK.CIR A_FORWARD.CIR A_RESO_DC.CIR A_RESO_OL.CIR Demonstrating Switched Models: S_FULL_VM.CIR S_FULL_CM.CIR S_HALF_VM.CIR S_HALF_CM.CIR S_BUCK_CM.CIR S_PUSH_VM.CIR S_FLYBACK_CM.CIR S_BUCKBOOST_CM.CIR S_FLYBACK_VM.CIR S_PUSH_CM.CIR S_BUCK_VM.CIR S_BOOST_VM.CIR S_BUCKBOOST_VM.CIR S_FORWARD_VM.CIR S_2FLY_CM.CIR S_BOOST_CM.CIR S_BUCK_SYN2.CIR S_BUCK_SYN.CIR S_FORWARD_CM.CIR S_FULL_XFMR.CIR S_HALF_XFMR.CIR S_2FOR_CM.CIR As an example consider the circuit below.

It is a Ben-Yaakov GSIM buck voltage mode averaged model that is set up so that you can run either AC or transient analysis. This circuit is set up to test the response of the output voltage to step change in load current in transient analysis and the small-signal open-loop gain in AC analysis. The conditional definition of the CL value opens the loop for AC analysis and closes it for the transient step response. Here is the open-loop AC analysis showing the output voltage gain and phase:

Here is the transient analysis step response.

The plot shows the response of the output voltage to a step change in the output resistance. The source V10 controls the switch S1, which has an off resistance of 25 ohms, producing a step change in the output current from about 80ma to about 400ma. The output voltage returns to the regulated value within about 1ms. The interesting thing here is that you can do a transient analysis on a model that is designed to be only an averaged or AC model. Of course you do not see the moment by moment inductor current switching or the output voltage ripple, because these behaviors have been averaged out in the construction of the model. The model is accurate enough however, to reproduce the large averaged time constants as demonstrated by the damped response to the output load change. In Figure 10 we show the output of the switched model responding to a similar step change in the output resistance and current. It shows more switching detail, but the overall damped response is about the same.

The switched model transient analysis required about 400 seconds to complete while the averaged model required about 4 seconds. Shorter run time is a major feature virtue of averaged models. To complete the review, here is another switched model. This is a simulation of a flyback current mode converter. Here is the schematic. At its heart is the PWMVM voltage mode controller.

Here are plots of the output voltage, the clipping current, the leakage current, and the drain-source voltage across the MOSFET switch.

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