Dedicated DSP Device Digitizes Analog Position Sensors
The iC-TW8 signal processor from iC-Haus converts signals from sine/cosine position sensors to incremental digital signals, using automatic functions to minimize angular errors and jitter. It supports push-button sensor calibration and continuous adaptation of sensor parameters during operation. Angular position is calculated with a programmable resolution of up to 65,536 increments per input cycle and output as indexed incremental signals from an SPI port.
The iC-TW8 integrates two analog/digital converters sampling simultaneously at 250 kSPS, fast CORDIC algorithms and special signal filters, as well as an analog front end with differential programmable gain inputs which accepts typical magnetic sensor signals from 20 mVpp upwards. Signal frequencies up to 125 kHz permit high rotary and linear speeds for position measuring devices and are processed with a constant latency of 24 µs. PWM signals and serial interfaces are provided for controller applications (1-wire interface and an SPI interface supporting clock rates up to 32 MHz). The 32-bit position register provides the angle data and period count; a second register provides information on the current angular speed.