Yoshimi Iso

High Quality FM Stereo Decoding IC with Birdie Noise Cancelling Circuit

The authors recently developed a stereo decoding IC which includes a new Birdie Noise cancelling cirucit. This new IC uses 12L for the digital circuit and bipolar transistors for the analog circuit.

Super High Quality FM Detector and its Development Process

An FM ratio detector has achieved signal-to-noise ratio of better than 90 dB and T.H.D. of less than 0.01% using a lower load factor and a new arrangement of detector coils with an index of coupling of 1.2 selected.

16-BIT A/D Converter and D/A Converter for Digital Audio

The Compact Disc Player has made a rapid popularization of so called digital audio using a PCM technique. And this fall, Digital Audio Tape-recorder (DAT) is expected to be commercialized. The A/D and D/A converters are two of key devices for DAT, so it is required to realize high performance, low cost and low power consumption.

A front-end for a digital satellite TV broadcasting receiver

A new front-end for a digital satellite TV broadcasting receiver has been developed. It consists of a tuner and a new analog quadrature detector (bipolar) IC which includes a broadband 90 degrees phase shifter and two multiplexers. The newly developed phase shifter is designed for application in Japan, the USA and Europe, covering an IF of 402.78 MHz to 379.5 MHz. This front-end can receive signals in the 920 to 2150 MHz band and output quadrature base band signals for QPSK demodulation at a low supply voltage of 5 V.

A Study On The Method on Double The Data Rate For Recording/reproducing And Search Speed For DAT

A method to double the search speed and the data transmission rate for recording/reproducing has been studied for a DAT (digital audio tape recorder). A high speed search up to 400 times the normal playback speed was realized. Using this DAT, the search time for programs from the beginning to the end of a 2-hour long tape was reduced to 26 sec from 44 sec, the latter value being that for a conventional DAT. With this technology, a high-speed search system has been developed for a DAT using magnetic tape as the recording medium. >

A Smart A/D Converter with tunable resolution and dynamic range for electric power meter

The A/D converter applied to electric power meter needs wide dynamic range. We propose Smart A/D Converter System which uses D/A converter, operational amplifier and analog switches, calibrates automatically and has wide dynamic range. We evaluated this proposal by general purpose MCU and got good result.

Automatic Loop Gain Control System Of Compact Disk (CD) Player's Tracking Servo

We developed the Automatic Loop gain Control System of CD Players tracking servo. It measures Frame error numbers with changing the loop gain in playback, and enlarges the loop gain by a fixed value from the loop gain when the error numbers increase suddenly. Consequently, we were able to decrease the lens actuator noise and to adjust the deviation of track loop gain by disc characteristics.