Flyback controllers are inherently isolated topologies which are ideal for offline (AC/DC) conversion. Flyback controllers are available with two control methods. The first is Primary-Side Regulation (PSR) which use the information from the auxiliary transformer winding to regulate the output and the other is Secondary-Side Regulation (SSR) which uses an optocoupler to provide more accurate feedback.
What are the pros and cons of Primary Side Regulation (PSR) vs. Secondary Side Regulation (SSR)? The following is a simple summary and a short list of popular controllers for each:
Figure 1-1 SSR
Control
|
Figure 1-2 PSR
Control
|
Pro – Tighter output voltage regulation (~2%) and faster load transient response Con – Requires Opto-coupler and shunt regulator |
Pro – No Opto-coupler and shunt regulator Con – Less accurate voltage regulation (~5%) and slower load transient response |
Are you wondering when to choose Continuous Conduction Mode (CCM), Discontinuous Conduction Mode (DCM), or Transition Mode also known as Critical Conduction Mode (TM/CrM)? Table 1-1 highlights the pros and cons of each.
Operating Mode | Pros | Cons | TI Product Family |
---|---|---|---|
CCM | Lower conduction and switching losses Improved cross regulation Smaller filtering solution |
Low light-load efficiency Higher diode reverse recovery loss More difficult to compensate and stabilize |
General Purpose PWM Controllers |
DCM | No diode reverse recovery loss Improved stability Potentially smaller transformer size |
Higher ripple currents Higher conduction and switching losses Larger filtering solution |
|
TM (CrM) | No diode reverse recovery loss Valley or Quasi Resonant (QR) switching Improved stability |
Higher ripple currents Higher conduction and switching losses if not used with valley switching or QR mode Larger filtering solution |
Dedicated Flyback Controllers |
Texas Instruments has Flyback controllers to support a wide variety of applications ranging from low power bias to high power density supplies. Our dedicated Flyback controllers combine our advanced control law to minimize switching losses and EMI by adjusting their switching frequency as a function of load. For high-power density or if you want to use a flyback more than 100 watts, check out our Zero-Voltage Switching (ZVS) and Active-Clamp Flyback (ACF) controllers.
Figure 1-3 is a quick selection guide for our controllers. To see more visit Flyback Controllers.
TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources.
TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2022, Texas Instruments Incorporated