Texas Instruments Incorporated (TI) introduced a smart bypass diode in a standard surface-mount package with 15-A current handling capability and the industry's lowest power dissipation.
In a typical application, each SM74611 lowers power dissipation by 80 percent and reduces the operating temperature inside the junction box by 50 degrees C when compared with a similar box using three conventional Schottky diodes.
 |
|
| SM74611 smart bypass diode in a typical junction box. |
When a photovoltaic (PV) solar 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 SM74611 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.
 |
|
| Typical Application Circuits. |
The SM74611 joins TI's family of solar products that include the UCD3138 digital power controller for solar micro-inverters, SM72441 maximum power point tracking controller and SM72295 full bridge driver.
The SM74611 functional diagram is shown below.
 |
|
| SM74611 Block Diagram. |
Key features and benefits of the SM74611 smart bypass diode
- 80-percent lower power dissipation than Schottky diodes reduces ambient temperature inside the junction box by 50 degrees C, improving the current rating of existing junction boxes, as well as enabling smaller boxes with improved current rating.
- Current handling up to 15 A with no avalanche effect.
- Reduced leakage current in both forward and reverse operation increases energy harvesting yield in PV arrays compared to traditional arrays using Schottky diodes.
- D2PAK package is a drop-in replacement for conventional surface-mount Schottky diodes.
Availability, packaging and pricing
The SM74611 smart bypass diode is available in volume now from TI and its authorized distributors. Offered in a two-terminal D2PAK package that measures 10.2 mm × 9 mm × 4.5 mm, the SM74611 is priced at US$1.50 in 1,000-unit quantities.
