A new ready-to-operate evaluation board is now available for high-resolution, 3-channel sine-to-digital converter iC-MN. It can be connected up to Hall or magnetoresistive angle sensors, or photosensor arrays in optical encoders. Plug-in sockets ease the testing of application-specific wiring using optional components. High-precision SAR converter iC-MN resolves phase angles from sine/cosine signals of up to 13 bits and has an excellent angle accuracy of typically 0.1 degrees.
Both the gain and the offset and phase correction of the integrated instrumentation amplifiers can be set separately for each of the three channels, enabling differential or referenced input signals. At the same time, the inputs can either be configured as high impedance for voltage signals from magnetic resistor bridges, for example, or switched to low impedance for the connection of photosensors that produce current signals. This thus permits the direct connection of various optical and magnetic sensors.
Each channel has a separate sample-and-hold stage that halts the signal for subsequent sequential digitization. The absolute angle value is output via the integrated serial 2-wire interface in SSI or BiSS C protocol at clock frequencies of up to 10 MHz. The RS422 transceiver required for this purpose is also integrated on chip iC-MN, so that the tiny QFN component, just 7 by 7 mm, takes up very little space.
Wolfgang Patelay, Editor Print & Online 