Showing papers on "Insulated-gate bipolar transistor published in 1979"

VMOS/Bipolar power switching device

Abstract: A relatively high power switching device is provided via the combination on a common substrate of a VMOS transistor having a gate electrode for receiving a control signal, a drain electrode, and a source electrode, individually connected to the collector and base electrodes of a bipolar transistor, respectively, the collector-emitter current path of the latter being the main current carrying path of the switching device.

Power MOSFET technology

Abstract: The recent development of high performance power MOSFET's threatens the Bipolar transistor monopoly on power control. Analysis of the presently available devices reveals several areas of superior performance. Properly designed power MOSFET's exhibit ultra-high speed operation, freedom from second breakdown, excellent temperature stability and large avalanche current capability. Near term improvements now under development suggest that power MOSFET's will have a dominant position in the 500 Volt and under power control market.

Design Considerations in Class D MOS Power Amplifiers

Abstract: The theory and design of high-efficiency Class D (Switching Mode) power amplifiers incorporating MOS power transistors are considered in this paper. Class D amplifiers suitable for servo, audio, and general purpose industrial applications are presented. Feedback techniques in Class D amplifiers are also examined.

VMOS/Bipolar dual-triggered switch

Abstract: A relatively high-power switching device and circuit includes a first VMOS transistor which is turned on for supplying via its channel a first current to the base electrode of a bipolar transistor, for turning on the latter into at least an unsaturated conduction state, thereafter a second VMOS transistor is turned on for supplying a second current concurrently with the first current to the base electrode of the bipolar transistor, causing the latter to go into or close to saturation as possible, depending upon the characterstics of the load, for minimizing the power dissipation thereof during a major period of its conductive state. The second VMOS transistor has its channel connected between the base and emitter electrodes of the bipolar transistor, whereby when the former is conductive, in addition to supplying the second current, it also provides negative feedback between the collector and base electrodes of the bipolar transistor, thereby enhancing the transient capability of the bipolar transistor. The bipolar transistor is turned off by first turning off the first VMOS transistor, ensuring the former is placed into a non-saturated conduction state, and thereafter the second VMOS transistor is turned off, reducing the base current to zero, causing the bipolar transistor to turn off. In this manner the turn-on and turn-off times for the bipolar transistor can be minimized.

Power switching transistors—A prognosis

Abstract: For switching regulator and other related applications, high-voltage bipolar transistors have long been a mainstay of the power semiconductor device industry. Recently, this position has been challenged by the development of power MOSFETs which have voltage and current control capabilities that compare favorably with the bipolar. In this paper, both devices are discussed. As one might expect, various properties of the lightly-doped collector (drain) region are crucial to the design of both transistors. The theoretical steady-state or conduction loss of both devices is compared on a per unit area basis. It is shown that the bipolar will usually have a smaller voltage drop. Thus to enjoy the advantage of the lower switching losses of the MOSFET, it is necessary to operate at a sufficiently high frequency.

Synthesis of matched b.j.t. cascode broadband amplifiers

Abstract: The letter describes a way to determine gain-bandwidth limitations of high-gain matched broadband amplifiers that are based on a cascode connection of bipolar junction transistors (b.j.t.s). An example is included to illustrate the method.

Design technique for broadband microwave transistor power amplifiers

Abstract: A technique for the design of broadband microwave transistor power amplifiers is presented that utilises the powerful methods of network synthesis to achieve optimum large-signal performance. Only two large-signal transistor measurements per frequency are required to achieve a good analytic model of the transistor's variation of added power with load impedance, and a mapping function is presented that translates this added-power characteristic into an equivalent linear-circuit reflection-coefficient characteristic. With this representation, methods of linear-network synthesis are used to obtain circuits which optimise the amplifier's added-power efficiency over a broad range of frequencies. The design technique has been experimentally verified by the characterisation, design and construction of a b.j.t. amplifier of near-octave bandwidth centred at 1 GHz, with the large-signal performance in good agreement with that predicted by the design theory.

Fall time characteristics of the Darlington transistor switching an inductive load

Abstract: In an inductive circuit the fall time delay of a Darlington transistor can be significantly longer than theory predicts. The increase is shown to be related to the rate of rise in collector voltage. By including this effect, a more general expression for fall time is developed.