iC-MSB
SAFETY
, iC-MSB2
SIN/COS SIGNAL CONDITIONER WITH 1Vpp DRIVER
Rev D2, Page 2/29
DESCRIPTION
iC-MSB is a signal conditioner with line drivers for
sine/cosine sensors which are used to determine po-
sitions in linear and angular encoders, for example.
Programmable instrumentation amplifiers with se-
lectable gain levels permit differential or referenced
input signals; at the same time the modes of op-
eration differentiate between high and low input
impedance. This adaptation of the iC to voltage or
current signals enables MR sensor bridges or photo-
sensors to be directly connected up to the device.
The integrated signal conditioning unit allows signal
amplitudes and offset voltages to be calibrated accu-
rately and also any phase error between the sine and
cosine signals to be corrected. Separate zero signal
conditioning settings can be made for the gain and
offset; data is then output either as an analog or a
differential square-wave signal (low/high level analo-
gous to the sine/cosine amplitude).
For the stabilization of the sine and cosine output sig-
nal levels a control signal is generated from the con-
ditioned and calibrated input signals which can power
the transmitting LED of optical systems via the inte-
grated 50 mA driver stage (output ACO). If MR sen-
sors are connected this driver stage also powers the
measuring bridges.
By tracking the sensor energy supply any signal vari-
ations and temperature and aging effects can be
compensated for and the set signal amplitude main-
tained with absolute accuracy. At the same time the
control circuitry monitors both whether the sensor is
functioning correctly and whether it is properly con-
nected; signal loss due to wire breakage, short cir-
cuiting, dirt or aging, for example, is recognized when
control thresholds are reached and indicated at alarm
output ERR.
iC-MSB is protected against a reversed power supply
voltage; the integrated voltage switch for loads of up
to 20 mA extends this protection to cover the overall
system. The analog output drivers are directly cable-
compatible and tolerant to false wiring; if supply volt-
age is connected up to these pins, the device is not
destroyed.
The device configuration and calibration parameters
are CRC protected and stored in an external EEP-
ROM; they are loaded automatically via the I2C in-
terface once the supply voltage has been connected
up.
A safety-technical analysis of iC-MSB on device level
with the inclusion of layout and internal/external cir-
cuitry has been carried out together with the BGIA,
St. Augustin. The result proved iC-MSB’s capability
for safety oriented applications with Siemens Sinu-
merik Controls.
ICHAUS [ IC-HAUS GMBH ]
