IC-LNB_13 Datasheet, PDF (2/35 Pages) IC-Haus GmbH – 18-BIT OPTO ENCODER WITH SPI AND SER/PAR INTERFACES

iC-LNB 18-BIT OPTO ENCODER ^preliminary
WITH SPI AND SER/PAR INTERFACES
Rev A1, Page 2/35
DESCRIPTION
iC-LNB is an 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 mono-
lithically 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 tempera-
ture and aging effects. The receive power setpoint
can be programmed. Should the LED current control
exceed its operating range, this is indicated at the er-
ror 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 4 to
2¹⁸ 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 inter-
face. 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.