Semiconductor History

Burr-Brown PCM1702-L I've just acquired from eBay a CD player to complement another very old CD player, both with Burr-Brown Digital to Analog converters. The photo shows the inside of the Denon CD-655 from the late 90s, a super low distortion and high signal to noise ratio CD player which uses 2 x PCM1702 DACs from Burr-Brown. The BiCMOS process 20-Bit PCM1702 was a really interesting DAC which was an improved version of the PCM63P. Early R-2R ladder DACs suffered from some noise/glitches at low output levels (and degraded linearity) due to the Most Significant Bit current source turning on at the lowest volume output point. Multi-bit DACs had significantly higher performance than contemporary 1-bit and "MASH" DACs, but had this one flaw. The PCM1702 was effectively two 19-bit DACs in a complementary design which negated the zero cross point issue. They had all the benefits of R-2R ladder DACs and now removed the other issue. Around this time Burr-Brown were al

Silicon npn transistors from Toshiba and Hitachi with an NEC pnp in the middle. Following the development of the point contact transistor at Bell Laboratories (and subsequent grown junction transistor development), Tokyo Tsushin Kogyu became the earliest Bell Labs transistor licensee in Japan. They moved quickly, producing their first transistor radio in August 1955. This was one year after Texas Instruments introduced the TR-1, the world's first production portable transistor radio. Tokyo Tsushin Kogyu, Hitachi, Tokyo Shibauro Electric, Mitsubishi Electric and Kote Kogyo became the first five Japanese transistor licensees of Bell Labs and Western Electric by July 1956. Tokyo Tsushin Kogyu became Sony and Tokyo Shibauro Electric became Toshiba. Semiconductor developments progressed quickly during the second half of the 1950s and by 1959 50% of transistor radios bought in the US were Japanese, or used Japanese transistors. Unlike in the US where the Defense market was s