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iC-RZ: Safe Scanning with Optical Twin-Scan Encoder 30.10.2019
Optical Twin-Scan Encoder IC with Safety Channel
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Simple adjustment and compact design for safety encoders: iC-Haus presents a 15-bit encoder chip with independent control and safety channels
With the iC-RZ Series encoder chips from iC-Haus, safety encoders can be made even simpler and more compact. This is made possible by the innovative single-chip design as an optical twin encoder with a redundant safety channel. The company offers the ICs for code disks with a diameter of 26.5 mm for 36 mm encoders or 42.5 mm for 58 mm encoders. Prime applications, for example, are ultra-compact SIL encoders for smart production environments and collaborative robots (cobots) or safety motors with integrated encoders.
The aperture is realized directly on the phased array IC. The photodiodes used are particularly sensitive to blue light. With short-wave light, higher resolutions can be achieved during the scanning process and lager tolerances simplify adjustment. Both sensor arrays are positioned ideally on the chip base so that only one component needs to be aligned precisely with the code disk.

Safety and control channel
The double scanning process by either incident or transmitted light is performed via a control channel and a safety channel which are completely independent of each other. This is ensured by shallow trench isolation on the chip and a separate power supply for the channels. These measures preclude Common Cause Failures (CCF).
The pseudo random code (consisting of two complementary tracks) encodes the absolute position over a word length of 10 bits. In addition, as the incremental track is read with 1024 CPR, the 5-bit on-chip interpolation of the sin/cos signals allows a total resolution of up to 15 bits to be processed.
Under laboratory conditions, the iC-RZ provides two 15-bit position words that can be transmitted using the BiSS Safety protocol, for example. In practice, 12 to 13 bits have proven to be sufficiently accurate for many safety applications.

24-bit resolutions with external interpolation Another high-resolution sin/cos track with 2048 CPR is scanned via an additional photodiode of the control channel. Using the iC-MR3 for example, the analog signal can be interpolated externally so that the iC-RZ Series is also suitable for high-resolution absolute encoders up to a maximum signal resolution of 24 bits.
The iC-RZ can also read safe multiturn information. Independent of safety applications, the encoder chip can also be used as a single-channel pseudo random code scanner for absolute position determination.

Fast implemetation and certification Safety encoders using the new iC-RZ can be certified up to SIL 3 or PL e. The use of the single-chip solution reduces the effort required for development and certification of safety encoders to a minimum. The high demand on redundancy can be met with just one component. iC-Haus provides manufacturers of encoders with a comprehensive “Implementation Handbook”.

Read more and download the datasheet:
Product iC-RZ Series
 
Product Overview
Application Guide