IC-MG_14 Datasheet, PDF (20/22 Pages) IC-Haus GmbH – 8-Bit Sin/Cos INTERPOLATION IC WITH RS422 DRIVER

iC-MG
8-Bit Sin/Cos INTERPOLATION IC WITH RS422 DRIVER
APPLICATION NOTES
Rev D1, Page 20/22
Circuit example for 1 Vpp sensors
Figure 5 introduces the principle input wiring to 1 Vpp
sensors. Here, resistor RS1 provides line termination,
and serial resistors RS2 and RS4 are providing ESD
and overvoltage protection together with iC-MG’s in-
ternal clamping circuit.
Resistor RS3 reduces the incoming signal levels to one
third, so that iC-MG can be operated at a total gain of
x3. The filter capacitors can be adapted, either de-
pending on the sensor’s noise level, or in accordance
with the desired maximum input frequency.
Using the analog ground GNDS for the filter circuit can
be recommend; the cable shield should be linked to
the external ground of the IC’s power supply.
CS1
2.2 nF
470 pF
470 pF
220 pF
—
Notes
CS2
CS3
fc -3 dB
2.2 nF
470 pF
ca. 115 kHz
470 pF
470 pF
ca. 170 kHz
470 pF
220 pF
ca. 180 kHz
220 pF
—
ca. 205 kHz
—
—
ca. 210 kHz
GRSC = 2, GFS = 1.5, GFC = 1.5
Table 41: Filter Cut-off Frequency (-3 dB)
In-circuit programming of the EEPROM
To avoid bus conflicts during in-circuit programming of
the EEPROM using external programming tools, iC-
MG should be supplied first and must have finished
its I2C master communication.
Alternatively, access to the EEPROM is unhindered as
long as iC-MG’s supply voltage remains below turn-
off threshold VDDoff. Programming of a 2.5V-capable
EEPROM can thus be possible. As iC-MG can be back
biased by I2C pull-up resistors, its supply voltage may
not exceed turn-on threshold VDDon.
Figure 5: Principle input wiring for 1 Vpp sensors.