Texas Instruments Inc. (TI) has launched the SM74611, a smart bypass diode in a standard surface-mount package with 15-A current-handling capability. In a typical application, each SM74611 lowers power dissipation by 80% and reduces the operating temperature inside the junction box by 50 degrees C when compared with a similar box using three conventional Schottky diodes, according to the company.
When a photovoltaic panel is shaded, the SM74611 active diode provides an alternate low-resistance path for string current to prevent hot spots that can damage the panel. The product thus protects the panel and improves PV solar panel reliability by boosting efficiency, and the reduced thermal dissipation enables more compact junction boxes with smaller heat-sinks, TI explains.
‘More stringent safety standards for junction boxes and increased currents from the newest generation of high-efficiency PV modules cannot be handled with conventional Schottky bypass diodes without significantly increasing the physical size of the junction box,’ says JÃ¶rg Schmidt, director of sales for PV-connecting systems at Kostal Industrial Electronics.
‘TI's SM74611 smart bypass diode enables us to easily increase the current rating of our line of SAMKO junction boxes from 10 A to 13 A without changing the physical design,’ he adds.