Description
iC-NV is a monolithic A/D converter which produces two digital A/B incremental signals phase-shifted at 90° from two sinusoidal input signals, also phase-shifted at 90°. The converter operates on the flash principle with fast single comparators. The back-end signal processing circuit includes a no-delay glitch filter which can be set so that only clearly countable incremental signals are generated. The minimum transition distance for outputs A and B can be set via an external resistor and adapted to suit the application on hand. For static input signals hysteresis prevents the switching of the outputs. By programming the pins the interpolator can be set to nine different resolutions between 4 and 64 angle steps per cycle; multiplication values of between 1 and 16 are possible for the frequency. The phase relation between the sine/cosine input signals and the A/B incremental signals generated can be selected here. The device also incorporates an index signal processing circuit which generates a digital zero pulse at Z dependent on the analog sine/cosine input signals and the enable input ZERO. Alternatively, the converter MSB can also be output at Z for synchronization purposes in an absolute measuring system. The input amplifiers are configured as instrumentation amplifiers and permit sensor bridges to be directly connected without the need for external resistors. The input amplification has nine selectable settings which have been graded to suit standard sensor signals of between ca. 10mVpk and 1Vpk. If external calibration of the sensor bridge is required, eg. with regard to offset, various test functions can be activated. By this the amplified analog input signals come available at the outputs, for instance.
Features