Description
The CMOS device iC-ML consists of four hall sensors arranged in a line and optimized to read out magnetic tapes with 2.56 mm pole spacing. This sensor array permits error-tolerant adjustment of the magnetic tape, reducing assembly efforts. The integrated signal conditioning unit provides a differential sine/cosine signal at the output. The sensor generates one sine/cosine cycle for each full magnetic periode of 5.12 mm, enabling the traveling distance to be clearly determined. At the same time the internal amplitude control unit produces an regulated output amplitude of 2 Vpp regardless of variations in the magnetic field strength, supply voltage and temperature. Furthermore, signals are provided which enable the sensor amplitude to be assessed and also report any magnetic tape loss. With the aid of the integrated 8-bit sine/digital converter the traveling distance within a magnetic periode is determined from the sine/cosine signals. This is output via an incremental interface in a number of selectable resolutions. The zero position of each periode is indicated by an index pulse. The maximum resolution of 8-bit is maintained up to traveling speeds of 5 m/s. The absolute position within a magnetic periode can be converted back to a linear analog output signal using the internal D/A converter; here, output voltage limits can be set as required using the external pins. Either a periodic linear signal (sawtooth) or a delta voltage (triangle) can be provided. iC-ML can be easily cascaded in three different modes of chain operation so that several axes of transition can be scanned. The linear positions of the individual axes can then be read via a common bus. Used in conjunction with a magnetic tape iC-ML can act as an linear encoder system with an integrated magnetic scanning feature.
Features