STMicroelectronics Introduces 250A Power MOSFET Combining Package and Process Advances for Higher Motor-Drive Efficiency
First discrete power MOSFET to deliver 1.5 milliohm on-resistance with high current handling for 55V applications.
Taking aim at reduced operating costs and lowering the environmental footprint in applications such as electric vehicles, STMicroelectronics (NYSE: STM), a world leader in power applications, has introduced a 250A surface-mount power MOSFET with the lowest on-resistance in the market, to minimize energy conversion losses and enable higher performance.
The new device, the STV250N55F3, is the first power MOSFET to combine ST's PowerSO-10 package with ribbon bonding to achieve ultra-low die-free package resistance. Implemented in ST's high-density STripFET III fabrication process, the device offers a typical on-resistance of 1.5 milliohms. Further benefits of STripFET III include low switching losses and rugged avalanche characteristics. The nine-lead source connection also reduces on-resistance, in addition to aiding heat dissipation. Overall, the package is rated for 300W dissipation at 25 degrees Celsius.
The high current rating allows engineers to design-out multiple parallel MOSFETs to save board space and cost. Standard driving thresholds also simplify driver-circuit design. The STV250N55F3 is rated for applications up to 55V.
The ability to operate at temperatures up to 175 degrees Celsius makes the STV250N55F3 suitable for use in high-current electric-traction applications such as forklift trucks, golf carts and pallet trucks, as well as lawnmowers, wheelchairs, and electric bikes. Reliability and robustness are assured through 100% avalanche testing both at wafer level as well as on finished products. In the future, the device will be eligible for automotive-grade applications.
Within the same family, ST also has the 55V STV200N55F3, which implements a four-lead source connection and is rated for 200A continuous drain current.
STripFET III Features
ST has just developed a new generation of the well known STripFET technology: STripFET III. This process is also known as EHD3 (Extremely High Density) resulting from the enhanced density of the equivalent cells, well above 57 Mcells/inch2.
EHD3 main feature is the strip width and the inter-strip gaps, which bring a considerable channel perimeter density: W=62m/cm2
High cell density and channel perimeter
Extremely low figure of merit
Optimized intrinsic recovery
The main electrical characteristics such as the current capability and RDS(on) are strictly dependent on the channel perimeter per unit area.
Very low RDS(on) gives low conduction losses
Cost effectiveness
Excellent switching behaviour
Reduced power losses of the diode.
Normalized figure of merit at 4.5V through the EHD generations
The EHD3, thanks to the decreased strip width, gains 38% in the channel perimeter per unit area, with respect to the second generation, this also means a great benefit in terms of RDS(on)
The figure of merit RDS(on) *Qg has been slashed by 43%. The EHD graph explains the trend in this parameter, which is of paramount importance in many applications.
On account of the main power supply requirement to operate at the highest efficiency, special attention has been given to the reverse recovery characteristic of the parasitic body diode.
In particular the Qrr is 39% smaller than in the previous EHD generations. Moreover, the low intrinsic resistance, Rg ( 1.9ohm is of outstanding importance to reduce the gate driving power losses. All these improvements are useful attributes in applications, especially for synchronous rectification for motherboard market, that allow us to consider the EHD3 technology as a benchmark in the low voltage scenario.
Further information is available at www.st.com/pmos
