Infineon TDA21535: A High-Efficiency 700 V Flyback Controller for Industrial and Consumer Applications

The demand for compact, reliable, and highly efficient power supplies continues to grow across both industrial and consumer electronics. Addressing this need, Infineon Technologies has introduced the TDA21535, a state-of-the-art 700 V flyback controller that sets a new benchmark for performance and integration in switched-mode power supplies (SMPS).

Engineered for robustness, the TDA21535 integrates a high-voltage startup unit, which significantly reduces standby power consumption and eliminates the need for an external startup resistor. This feature is critical for meeting stringent energy efficiency standards like ENERGY STAR and the European CoC V5 tier-2 specifications. Its 700 V avalanche-rugged power MOSFET ensures exceptional reliability, even in harsh industrial environments with volatile line voltages and frequent surge events.

A key strength of this controller lies in its quasi-resonant (QR) operation mode. This technology enables valley switching, which minimizes switching losses and electromagnetic interference (EMI). The result is a power supply that operates at a higher overall efficiency across a wide load range, from full load down to light load and standby conditions. This makes it an ideal solution for applications such as industrial motor drives, home appliances, smart meters, and auxiliary power supplies for white goods.

Furthermore, the IC incorporates a comprehensive suite of advanced protection features. These include cycle-by-cycle current limiting, overload protection (OLP), an adjustable brown-in/out function, and overtemperature protection (OTP). These built-in safeguards enhance system durability and prevent catastrophic failures, thereby reducing design complexity and improving field reliability.

The device also offers significant design flexibility. With adjustable switching frequency and a dedicated deep burst mode control pin, designers can fine-tune the performance to optimize the trade-off between audible noise and low-load efficiency. Its high level of integration simplifies the external bill of materials (BOM), leading to a more compact PCB layout and lower overall system cost.

ICGOO FIND: The Infineon TDA21535 emerges as a superior flyback controller, masterfully combining high voltage robustness, quasi-resonant operation for peak efficiency, and a full suite of protection mechanisms. It is a powerful enabler for designing next-generation, eco-conscious power supplies that do not compromise on performance or reliability.

Keywords: Quasi-Resonant Operation, High-Voltage Startup, 700 V MOSFET, Energy Efficiency, Protection Features.