IC-MSA Datasheet, PDF (27/29 Pages) IC-Haus GmbH – SIN/COS SIGNAL CONDITIONER with AGC and 1Vpp DRIVER

iC-MSA SIN/COS SIGNAL
preliminary
CONDITIONER with AGC and 1Vpp DRIVER
APPLICATION HINTS
Rev A1, Page 27/29
PLC Operation
There are PLCs with a remote sense supply which require longer for the voltage regulation to settle. At the same
time the PLC inputs can have high-impedance resistances versus an internal, negative supply voltage which
define the input potential for open inputs.
In this instance iC-MSA’s reverse polarity protection feature can be activated as the outputs are tristate during the
start phase and the resistances in the PLC determine the pin potential. During the start phase neither the supply
VDD nor the output pins, which are also monitored, must fall to below ground potential (pin GND); otherwise the
device is not configured and the outputs remain permanently set to tristate.
In order to ensure that iC-MSA starts with the PLCs mentioned above pull-up resistors can be used in the en-
coder. Values of 100 kΩ are usually sufficient; it is, however, recommended that PLC specifications be specifically
referred to here.
Connecting MR sensor bridges for safety-related applications
For safety-related applications iC-MSA requires an external overvoltage protection of supply VDD (Zener diode
with fuse, for instance) and external pull-down resistors at the inputs X3 to X6 towards GNDS (of up to 100 kΩ).
VP
SCL
24xx
SDA
VN
R5 R6
4.7kS 4.7kS
C1
100nF
SCL
SDA
VDDS
VDD
I²C
iC-MSA
AUTOMATIC
GAIN
CONTROL
ERR
C2
100nF
PZ
MR0
MR1
MR2
X1
+
- ^X2
INPUT ZERO
X3
X5
R1
R2
100kS 100kS
+
-
INPUT COS
X4
X6
R3
R4
100kS 100kS
+
-
INPUT SIN
GNDS
NZ
PC
NC
PS
NS
GND
F1
D1
5.6V
TVS diode array
Figure 8: Example circuit for safety-related applications with iC-MSA.
+5V
ERR
RL
100S
RL
100S
RL
100S
0V