MLX16305 Datasheet, PDF (2/29 Pages) Melexis Microelectronic Systems – Interlock switch sensor interface IC

MLX16305
Interlock switch sensor interface IC
1. Overview application Schematic
VBAT
VSUP
78L05
Resistive Rotary Encoder
Renc Renc Renc Renc
VDD
ADC
Microcontroller
GND
MEAS_OUT
ENABLE
VI_CTRL
MUX_SENSE1
MUX_SENSE2
MUX_SENSE3
VREF VSUP
Sense1
Sense2
Sense3
MLX16305 Sense4
Sense5
Sense6
GND
RREF
(Rs2)
(Rs3)
Rs6
VBAT
Switch to VBAT
(Rp2)
Switch to GND
Rref
Seat
Interlock Switches
Occupant _{Resistive and 2-wire Hall}
2. Description
The MLX16305 is designed to diagnose the state of remote interlock switches in automotive safety
applications. Its high accuracy allows it to be applied in a broad range of related automotive and
industrial applications using current modulated sensors and switches.
The MLX16305 includes a current-limited regulated supply that is applied to one channel (switch/sensor)
at a time. The supplied current or the resulting supply voltage are measured and presented as an analog
voltage to the microcontroller for interpretation.
Each MLX16305 allows scanning up to 6 switches for changes in switch state, and for any type of
short/open circuit failure mode. The range of switches can easily be extended by adding other
MLX16305 devices in parallel on the same microcontroller ADC input.
The high current and voltage range allow maximum contact cleaning energy for resistive switches. The
high accuracy allows monitoring of contact ageing and early failures detection.
3901016305
Rev. 005
Page 2 of 29
Data Sheet
Oct/06