Description
iC-LNB is an 18-bit optoelectronic encoder IC for absolute linear and angle measuring systems, such as glass scales and encoders. Photodiodes, amplifiers, and comparators, the entire signal conditioning unit, and interfaces for position data output have been monolithically integrated into the device. An integrated LED current control with a driver stage allows a transmitting LED to be directly connected (e.g. iC-SN85). The optical receive power is kept constant by the control unit, regardless of temperature and aging effects. The receive power setpoint can be programmed. Should the LED current control exit its operating range, this is indicated at the error message output (end-of-life alarm at pin ERR). The photocurrent offset and photocurrent amplitude of the analog sine/cosine signals can be calibrated. These calibrated voltage signals are lead out to pins PSIN, NSIN, PCOS, and NCOS and are used by the integrated 8-bit vector-tracking interpolation circuit. iC-LNB synchronizes the interpolator and singleturn data to form a contiguous Gray-coded position data word. 16 parallel ports, a scalable shift-register, the SPI interface, as well as incremental A/B/Z signals are available for data output. By help of the unique FlexCount® circuit any angle resolution between 1 to 216 angle steps per revolution can be preset for the incremental signals and the absolute position value. After startup iC-LNB is configured using the SPI interface. To make connection to a 3.3 V microcontroller easier, all digital I/O ports, including the SPI, can be run on 3.3 V.
Features