In order to control speed and positioning, drive controllers require high-resolution magnetic or optical position sensors.
In order to control speed and positioning, drive controllers require high-resolution magnetic or optical position sensors. These sensors also need highly integrated ICs for signal conditioning and sine/cosine-to-digital conversion.
In response, iC-Haus GmbH created the iC-MQF ASIC to provide fast sine evaluation and a sine resolution of up to 4,000 edges. The IC incorporates a signal conditioning analog front end (AFE), a vector-tracing converter for real-time no-latency conversion, and fault-tolerant RS422 driver stages that output incremental signals. The device also embeds reverse polarity protection that covers all cable connections.
Analog signal corrections including offsets, amplitude mismatch, and phase errors result in high interpolation accuracy. Measurement accuracy is maintained after an initial adjustment by tracking sensor excitation.
Flexibility is provided to designers since the chip’s error handling is configurable -- an alarm can be displayed via an LED, and the user can set output drivers to tristate or to be transmitted to error memory for later analysis. Encoder signals are supplemented by a generated index signal whose position, width, and logic can be selected.
With a single +5 V supply, device functions are within an operating temperature range of -40 to +100° C. iC-MQF also protects the connected sensor circuit against a reversed supply voltage.
A ready-to-operate demo board with a GUI is available for sampling; a device DLL is optional to support production tools. Contact iC-Haus for more information as to availability and the demo board.
iC-Haus designs ASICs for industrial, automotive, and medical industries. The company, supporting this latest IC, created a whitepaper that provides users with a thorough and highly technical explanation of sine/cosine to digital conversion methods. It can be downloaded here.
— Carolyn Mathas is a freelance blogger and editor for EE Times's Industrial Control Designline.