1999-04-01 , E/DS-1052/11
Product News From Philips Semiconductors

With the introduction of its new 'Breakthrough In Small-Signal' switching transistors, Philips Semiconductors, the largest European semiconductor manufacturer, adds the benefits of extremely low collector-emitter saturation voltage to the inherently low turn-on voltage of bipolar transistors, giving designers the advantage of reduced power dissipation in low-voltage battery-powered equipment such as mobile phones and pocket pagers.

"For switching low-voltage loads at peak currents up to one or two amps, silicon bipolar transistors still remain the favoured device for many design engineers because of their lower turn-on voltage and better peak current handling capabilities compared to MOSFETs," said product marketing manager Andreas Niemann. "Our new Breakthrough In Small-Signal transistors mean significantly lower power dissipation in the switching transistor, resulting in considerably longer battery life for mobile equipment."

To achieve typical V_CE(sat) figures as low as 0.25 V and DC current gains of over 200 for SOT23 packaged versions operating at a collector current of 1 A, Philips Semiconductors developed an innovative emitter structure for these new transistors that reduces the bulk emitter resistance. In addition to reducing power dissipation by keeping the emitter resistance low, Breakthrough In Small-Signal transistors have also been designed to maintain their performance at high junction temperatures. These two features allow the SOT23 packaged versions (the npn  PMMT491A and pnp  PMMT591A) to handle continuous load currents as high as 1 A - twice the load current capability of conventional SOT23 transistors. It also means that in many applications these transistors can be operated without any additional heatsinking.

The two complementary SOT223 packaged transistors in the initial range (the  BDL31 and  BDL32) can handle currents as high as 5 A, and will soon be joined by two more 5A SOT223 packaged versions (the PBSS4540Z and PBSS5540Z) featuring further reductions in V_CE(sat) and higher breakdown voltages. SOT89 packaged versions are also scheduled for introduction this year. The high peak current ratings of Breakthrough In Small-Signal transistors makes them particularly suitable for small motor control.

Volume deliveries of all types are available now with prices ranging from Hfl 0.15 for the SOT23 devices to Hfl 0.29 for the SOT223 devices in volumes of 100k pieces.

Philips Semiconductors, a division of Royal Philips Electronics, headquartered in Eindhoven, The Netherlands, is the eighth largest semiconductor supplier in the world (according to Dataquest's preliminary 1998 ranking by sales) and the third largest supplier of discretes in the world. Philips Semiconductors' innovations in digital audio, video, and mobile technology position the company as a leader in the consumer, multimedia and wireless communications markets. Sales offices are located in all major markets around the world and are supported by systems labs.