History 2N3055

2n3055 transistors have several applications in power circuits, including inverters , voltage regulators.

the historically-significant 2n3055 designed herb meisel s engineering group rca; first multi-amp silicon power transistor sell less 1 dollar, , became industry workhorse standard. 2n3054 , 2n3055 derived 2n1486 , 2n1490 after package redesigns milt grimes. team of design, production, , applications engineers received rca electronic components achievement awards in 1965. 2n3055 remains popular series pass transistor in linear power supplies , still used in medium-current , high-power circuits generally, including low frequency power converters although use in audio power amplifiers , dc-to-ac inverters less common , use in higher frequency switch-mode applications never practical. second sourced other manufacturers; texas instruments listed single-diffused mesa version of device in august 1967 datasheet. 1 limitation frequency response rather low (typically unity-gain frequency or transition frequency, ft, 1 mhz). although adequate of low-frequency workhorse applications, , par other high power transistors around 1970, did bring difficulty high fidelity power amplifier designs around 20 khz, gain began fall , phase shifts increased.

mid 1970s

with changes semiconductor manufacturing technology, original process became economically uncompetitive in mid-1970s, , similar device created using epitaxial base technology. maximum voltage , current ratings of device same original, not immune secondary breakdown; power handling (safe operating area) limited @ high voltage lower current original. however, cut-off frequency higher, allowing newer type of 2n3055 more efficient @ higher frequencies. higher frequency response has improved performance when used in audio amplifiers.

although original 2n3055 went decline relative epitaxial-base transistors because of high manufacturing costs, epitaxial-base version continued used in both linear amplifiers , switching supplies. several versions of 2n3055 remain in production; used in audio power amplifiers delivering 40 w 8 ohm load

in push–pull output configuration.