MLX90711 Datasheet, PDF (8/12 Pages) List of Unclassifed Manufacturers – Position/movement Sensing Auto-Shutoff

MLX90711
Position/movement Sensing Auto-Shutoff
Application Example
PCB
D1
R1
90711
VDD1
CA0
LEDP
CA1
SUM _VSS ^RD
LED1
REL1
L
Load
D2
C1
N
The above drawing shows the electrical schematic of a typical application.
The asic is directly connected to the AC line via a resistor R1 and diode D1, thus supplying the asic during
only the positive cycle of the AC line voltage. A capacitor C1 is therefore added between VDD1 and VSS to
smooth the asic supply voltage. The asic will limit the voltage at VDD1 at approximately 60V. A 12V relay
REL1 can be used to load the pin RD. The relay is driven with a well defined duty cycle to ensure that the re-
lay is driven with the right energy. The relay driver needs a flyback diode D2. A led LED1 can be added to
indicate the state of the asic. If no led is used, it must be replaced by a short circuit.
Special care must be paid to the layout of the sensor on the pcb and to the connections between sensor and
asic. The asic is designed to detect very small variations in capacitance in the sensor. Therefore parasitic ca-
pacitances must be kept as small as possible, and injection of noise must be avoided.
MLX90711 Position/movement Sensing Auto-Shutoff Page 8
Rev 1.0 15/Sep/00