iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
Rev D1, Page 2/59
DESCRIPTION
Encoder device iC-MN is a 3-channel, simultaneous For the purpose of input signal stabilization the con-
sampling sine-to-digital converter which interpolates ditioned signals are fed into signal level controllers
sine/cosine sensor signals using a high precision featuring current source outputs of up to 50 mA (mas-
SAR converter with a selectable resolution of up to ter channel) and of up to 10 mA (for the nonius and
13 bits. Each input has a separate sample-and-hold segment channels each). These ACOx source pins
stage which halts the track signal for the subsequent either power the LEDs of an optical encoder or the
sequential digitization. Various 2- and 3-track Vernier magneto resistor bridges of a magnetic encoder. If
scale computations (after Nonius) can be configured the control thresholds are reached this event can be
for the calculation of high resolution angle positions; released for alarm messaging using the serial inter-
these computations permit angle resolutions of up to face or the NERR output.
25 bits.
Both major chip functions and sensor errors are also
The absolute angle position is output via the serial monitored and can be enabled for alarm indication.
Interface with clock rates of up to 4 Mbit/s (SSI com- In this manner typical sensor errors, such as signal
patible; up to 10 Mbit/s with BiSS C protocol). The loss due to wire breakage, short circuiting, dirt or ag-
RS422 transceiver required to this end is integrated ing, for example, can be signaled by alarms.
on the chip and has both a differential clock input and
a differential line driver for data output.
The device features further digital encoder functions
covering the correction of phase errors between the
Programmable instrumentation amplifiers with a se- tracks, for example, or the zeroing or presetting of a
lectable gain and offset and phase correction can specific position offset for data output. Using the SSI
be adjusted separately for each channel; these al- master also integrated on the chip position data from
low differential or single-ended input signals. At multiturn sensors, provided by a second iC-MN, for
the same time the inputs can either be set to high example, can be read in and synchronized.
impedance for voltage signals from magneto resistor
sensor bridges, for example, or to low impedance for iC-MN is protected against a reversed power supply
adaptation and use with photosensors which provide voltage; the integrated supply switch for loads of up
current signals, for instance. This enables the device to 20 mA extends this protection to cover the over-
to be directly connected up to a number of different all system. The device is configured via an external
optical and magnetic sensors.
EEPROM.