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Copyright LZE GmbH 2021
Package and Circuit Connection
Eine gemeinsame Initiative von
3.3
Electrical Connection
The sensor chip must be connected to a supply of 3.3V via its VDD and VSS pins. All unused pins should
be connected to VSS to guarantee proper function. A decoupling capacitor between VDD and VSS close
to the sensor chip is strongly recommended as well as the usage of non-magnetic components nearby to
prevent magnetic interference.
For communication of a single sensor with a microcontroller, all four SPI signals CS_N, SCK, MOSI and
MISO have to be connected. Fast digital signals (like clock and data signals) should be terminated with
series resistors near the transmitting device to prevent disturbing signal reflections.
It is recommended to use the two additional signals READY and RESET_N to recognize finished
measurements and execute a proper reset cycle of the sensor chip. If multiple sensors are connected to
the same lines, a pull-down resistor for the READY signal should be used.
For optional usage of low power mode or an external clock generated by the controller, LOPOWR and
CLK have to be wired properly, whereas the CLK signal also should be terminated with a series resistor
at the µC. If PMW output is used, the corresponding signal has to be wired to the receiver.
A1 M I SO
B2 M O SI
B5 SCK
A6 CS_N
C1 READ Y
C2 RESET_N
A5 LOPO W R
A2 CLK
C6 PW M
C4 VDD
C3 LOCK_N
A4 SCE
A3 V SS
B3 V SS
B4 V SS
C5 V SS
FH3D02 µC
VDD
GND
M I SO
M O SI
SCK
CS_N
READ Y
RESET_N
LOPO W R
CLK
RES5
CAP1
RES1
RES2
RES3
RES4
Recommended additional components:
CAP1: Non-magnetic capacit or near pins (100µF)
RES1: Non-magnetic series resistor matching line impedance at sensor (50Ω - 100Ω)
RES2 – RES4: Series resistor mat ching line impedance at µC (50Ω - 100Ω)
RES5: Pu l l -down resistor when using multiple sensors on same SPI bus (12kΩ)
mand atory
recommended
optional
Please note:
It is strongly recommended to use a PCB with wide bandwidth, low impedance supply layers and
impedance controlled digital signal lines with matching series resistors to the hardware setup.
A stable supply and clean signals are mandatory for low sensor noise and faultless
communication at high SPI frequency.