MLX16305 Datasheet, PDF (26/29 Pages) Melexis Microelectronic Systems – Interlock switch sensor interface IC

MLX16305
Interlock switch sensor interface IC
16.4. Ground Shift
The MLX16305 allows connecting a remote ‘2-wire’ hall sensor with only 1 wire.
Since the current is directly sensed, the measurement itself is immune to ground shift.
Furthermore [Vref – Vgroundsift] should be guaranteed to be larger than the minimum supply current for
the hall sensor. For instance for Vsupmin = 3.5V, and Vref = 5V, a groundshift of 1.5V is acceptable.
Therefore the ground can be taken local from the chassis, reducing the connector pin count on the safety
ECU, and reducing the wiring of the cables from the ECU to the remote sensors.
MCU
ADC
MCU
ADC
MCU
ADC
V_OUT
VDD
GND
A) 3-Wire Hall
10nF
VDDmin
I_SENSE
B) 2-Wire Hall
I_SENSE
VDD
I_OUT
GND
10nF
VDDmin
VDD
I_OUT
GND
10nF
C) ‘Single’-Wire Hall using MLX16305
3901016305
Rev. 005
Page 26 of 29
Data Sheet
Oct/06