ST Microelectronics , providers of power semiconductors, have increased the ruggedness, switching performance and efficiency of power MOSFETs for lighting ballasts, where they were used in the PFC and Half Bridge sections as well as in switching power supplies. The use of the SuperMESH3 technology with lower on-resistance provides higher efficiency. Additionally, due to their superior dv/dt performance and higher breakdown-voltage margin, these new devices provide enhanced reliability and safety.
The first SuperMESH3 device introduced was the 620V STx6N62K3, followed by the 620V STx3N62K3, the 525V STx7N52K3 and STx6N52K3. The savings in on-resistance enabled by SuperMESH3 reduce RDS (on) in DPAK packages to 1.28 Ohms in the 620V STD6N62K3 and 0.98 Ohms in the 525V STD7N52K3, boosting operating efficiency in applications such as low-energy lamp ballasts. The new technology also reduces reverse-recovery time (Trr), gate charge and intrinsic capacitance, leading to improved switching performance and enabling higher operating frequencies.
As a further advantage of the SuperMESH3 technology, which combines strip topology with an optimised vertical structure, the new devices exhibit dv/dt behaviours. This provides safety in lighting and other consumer electrical applications. All SuperMESH3 devices are 100 per cent avalanche tested and incorporate zener protection to deliver all-round robust performance.
By achieving the lowest on-resistance per area among comparable high-voltage, fast-recovery technologies, the SuperMESH3 allows the STx6N62K3, STx7N52K3, STx3N62K3 and STx6N52K3 to use smaller packages such as the DPAK. This saves footprint and board size and matches the switching and thermal performance of physically larger devices.
The STx6N62K3 is available in IPAK, DPAK, TO-220 and TO-220FP packages. The STx3N62K3 at 2.5 Ohms will be available in IPAK, DPAK, D2PAK, TO-220 and TO-220FP packages. The STx7N52K3 at 0.98 Ohms will be introduced in DPAK, D2PAK, TO-220, and TO-220FP packages and the STx6N52K3 at 1.2 Ohms will be available in DPAK and TO-220FP packages.