IC-TW11 Datasheet, PDF (11/25 Pages) IC-Haus GmbH – 10-BIT ULTRA LOW POWER MAGNETIC ABSOLUTE ROTARY ENCODER

iC-TW11 10-BIT ULTRA LOW POWER^preliminary
MAGNETIC ABSOLUTE ROTARY ENCODER
ELECTRICAL CONNECTIONS
Rev B1, Page 11/25
The basic electrical connections for the iC-TW11 are controller and a few passive components are required
shown in Figure 4. Only a host microprocessor or micro- for operation.
3.3DV
1.8DV
V_CORE
V_IO
1µF
iC-TW11
SAMPLE
IRQ_IN
GND
xSS
SCLK
SI
SO
IRQ_OUT
xRST
100nF
VDD
µP
xCS
SCLK
MO
MI
IRQ
Figure 4: Basic electrical connections
The iC-TW11 has two power supply inputs. V_CORE
(pin 15) is the main 3.3V power supply input and it must
be well bypassed to provide a low impedance power
source. This is important because the current consump-
tion of the iC-TW11 is approximately 10 mA while active
and current is drawn in short pulses. Depending on
the quality of the V_CORE supply it may be necessary
to use additional capacitors and/or supply filtering to
achieve the required stability.
The iC-TW11 reset input xRST (pin 14) is typically
driven from the host µP as shown. Alternatively, a
sufficiently slow RC network can be connected to xRST
for use as a reset source. R = 47 kΩ and C = 100 nF pro-
vide about a 5 millisecond time constant which should
be adequate for most applications.
The four SPI lines should be connected to their corre-
sponding pins on the host µP as shown.
V_IO (pin 12) is a separate power supply input that sets
the operating level of the I/O signals. V_IO can range
from 1.8 V up to V_CORE and it should also be well
bypassed. Typically, a 1.8 V supply would be used to
power the host microprocessor and the iC-TW11 V_IO
input as shown in Figure 4.
To use the iC-TW11 in its default condition (i.e. without
any configuration), it is necessary to connect IRQ_IN
(pin 9) to ground as shown to allow proper interrupt gen-
eration at IRQ_OUT. If external sampling is not used,
SAMPLE (pin 13) should also be tied to ground as
shown to avoid spurious samples. The five reserved
pins (1-4 and 6) must also be tied to ground for proper
operation (not shown above).