Bipolar power transistor rivals MOSFET energy efficiency in space-saving outline

September 26, 2013 // By Graham Prophet
The STMicroelectronics 3STL2540 combines the cost and silicon-area efficiencies of a bipolar transistor with energy efficiency similar to MOSFETs of comparable rating, giving designers a space-saving solution for cost-conscious power-management applications and DC-DC converters.

The 3STL2540 is a -40V/-5A PNP transistor capable of full saturation with maximum voltage drop of 200 mV at 10 mA base current. It can achieve an equivalent on-resistance of only 90 mΩ, which is close to the performance of comparable super logic-level MOSFETs.

ST’s advanced double-metal planar base island technology enables the 3STL2540 to maintain consistently high current gain (hFE) of at least 100 over a wide output-voltage range from 0.2 to 10V and a temperature range from -30°C to 150°C, offering lowest conduction losses for this type of device. The thermally efficient PowerFLAT package is only high with a 2 x 2mm footprint enabling reliable, high-performance power circuitry within minimal pc-board space. The 3STL2540 costs from $0.30 in the PowerFLAT 2x2 package (1,000).