iC-MSBSAFETY, iC-MSB2
SIN/COS SIGNAL CONDITIONER WITH 1Vpp DRIVER
Rev D2, Page 18/29
INPUT CONFIGURATIONS
RIN12
RIN0
Code
–000
–010
–100
–110
1—1
0—1
Adr 0x0E, bit 3:0
Input Configurations
Adr 0x13, bit 3:0
All input stages are configured as instrumentation am-
plifiers and thus directly suitable for differential input
signals. Referenced input signals can be processed as
an option; in this mode input X2 acts as a reference.
Nominal Rin() Intern Rui()
I/V Mode
1.7 kΩ
2.5 kΩ
3.5 kΩ
4.9 kΩ
20 kΩ
1.6 kΩ
2.3 kΩ
3.2 kΩ
4.6 kΩ
5 kΩ
current input
current input
current input
current input
voltage input
voltage input
INMODE
Adr 0x03, bit 2
Code
0
Function
high
impedance
1 MΩ
Differential input signals
Single-ended input signals *
* Input X2 is reference for all inputs.
1
Note
Table 18: I/V Mode and Input Resistance
Table 17: Input Signal Mode
BIAS12
BIAS0
Code
0
Adr 0x0E, bit 6
Adr 0x13, bit 6
VREFin()
2.5 V)
Both current and voltage signals can be processed as
input signals, selected using RIN12(0) and RIN0(0).
In I Mode an input resistor Rin() becomes active at
each input pin, converting the current signal into a volt-
age signal. Input resistance Rin() consists of a pad
wiring resistor and resistor Rui() which is linked to the
adjustable bias voltage source VREFin(). The follow-
ing table shows the possible selections, with Rin() giv-
ing the typical resulting input resistance (see Electri-
cal Characteristics for tolerances). The input resistor
should be set in such a way that intermediate poten-
tials VDC1 and VDC2 lie between 125 mV and 250 mV
(verifiable in Calibration Mode 2).
Type of sensor
Lowside sink current (I Mode)
Highside current source (I Mode)
1
1.5 V)
Table 19: Reference Voltage
BIASEX
Code
0-
Adr 0x0D, bit 7:6
VREFin()
internal
Signal at X2
Neg. Zero Signal (Index -), input
Ref. Voltage VREFin12, output
Ref. Voltage VREFin, input
10
internal *
external *
11
Note
*) The voltage at X2 is reference for all inputs.
In V Mode an optional voltage divider can be selected
which reduces unacceptably large input amplitudes to
ca. 25%. The circuitry is equivalent to the resistor
chain in I Mode; the pad wiring resistor is considerably
larger here, however.
Table 20: Input Reference Selection
Figure 2: Input instrumentation amplifier and signal conditioning
ICHAUS [ IC-HAUS GMBH ]
