SMPS300RE is a dedicated Switched Mode Power Supply for Audio Amplifiers. Enhanced Version of the previous SMPS300R, with dual CLC filter on the output section and compact profile power transformer, suitable for low-noise and high-end Power Amplifiers, both Class AB and Class D/T. It uses Half Bridge resonant topology, capable of delivering 300W continuous and up to 400W peak power with crest factor at least 2.5. SMPS300RE has by default differential output voltage, for single output voltage, refer to SMPS300RS. The stock available output voltages are adjustable within approx. 10% and the ordered voltage value is at the middle of the interval. For example the 30V version can be adjusted from 28V to 32V. In this way, the available voltage versions covers almost all the voltage range from 22V to 75V or eve more when custom voltage is chosen. The main feature of this power supply is the absence of the heatsinks both for power switches and rectifier diodes, due to increased efficiency, up to 94.6% for higher voltage versions, due to the fact that the transistors are soft-switched, and the current through the switches has sinusoidal shape, and there are no additional losses in output inductors. Also, the amount of EMI is much lower than any competitor’s SMPS especially the old, hard-switched type commonly found on the market and could be compared with a high quality linear regulated power supply. The size and weight is greatly reduced, allowing to install the SMPS300R to be installed into low profile case, with it’s 100x100mm and 32 to 40mm tall depending on the voltage version and capacitors used. The SMPS300R features over-current protection which limit the output current at about 130% of the maximum peak power, about 400W.
The Aux. Output Voltage is differential, unregulated and the value is approximately multiple of 5.5 to 6.5V. For example the Main Output Voltage of the 36V Version can be adjusted from approx. 22.5V to 26V while its aux. Voltage will follow the Main output approx. as 1/2V at +-18V, measured with 100-200mA load across V- and V+. For some main output voltage versions the aux. output voltage can vary within +-16.5V and +-20V. Also when the aux. output is unloaded the voltage will be slightly higher than when it is loaded.
This power supply is suitable for both class AB and class D/T amplifiers, which have the PSRR greater or at least 57dB. Target applications for this power supply unit include the TA2022 based amplifiers, TDA8920 or TDA8950 based amplifiers and IRS2092 amplifiers for the +-30V or +-36V version as well as other vendors amplifiers such as Hypex UCD180 Amplifier modules, TK2050 amplifiers or TDA7293/4 amplifiers.