What is the relationship between the frequency applied to the EN/SYNC pin and the frequency generated at the PWM outputs?
Peter James Miller
Power Management - DC/DC Solutions - Industrial & Communications DC Solutions
Member Group Technical Staff 2008
The TPS40090 controller's internal synchronization circuit uses an internal divide by 2 synchronization circuit to produce a 50% duty cycle SYNC signal and then multiplexes this signal to the PWM outputs.
In 2-phase or 4-phase modes, the PWM output frequency is 1/4 of this divided signal (4-phase multiplexed) generating a 1/8 switching frequency at the PWM output.
In 3-phase mode, the internal frequency is multiplexed over 3 channels to generare a 1/6 switching frequency at the PWM output.
The TPS40130, TPS40131, TPS40132, TPS40140 and TPS40180 use similar clocking schemes, producing the same divide by 8 or divide by 6 relationship between their SYNC or CLKIO inputs and their switching outputs.
Two TPS40090/91 controllers using a 180 degree out of phase 50% duty cycle SYNC pulse train will synchronize 45 degrees out of phase at 1/8 the switching frequency. It is not possible to synchronize two 2-phase TPS40090/91s 90 degrees out of phase (They will be randomly 0 or 90 degrees out of phase, depending on the divide by 2 state at start-up)
Also Note: Since the TPS40130/131/132 uses the same divide by 8 scheme is also used for the TPS40130/131/132, it is not possible to synchronize two TPS40130/131/132 controllers 90 degrees out of phase.
In reply to Peter Miller13277:
I have a question about TPS40090,How to get “TPS40090 Pspice model”for simulation?
In reply to Roger Ding:
I don't think we have Pspice model of TPS40090/91 so far.
In reply to Na Kong:
All available Pspice models can be found at:
or in the product folder. If you need a model that is not available, you can contact the Product Information Center by going to www.ti.com and clicking on technical support. They will assist you in determining if a model can be provided.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.