Intelligent Drivers and Actuators Sensor Interface The MLX16305 is designed to diagnose the state of remote interlock switches in automotive safety applications (40V Load-dump). 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. Multiple MLX16305 devices can be applied in parallel to scan 6/12/18/... channels. RF & RFID MLX16305 Automotive ICs Interlock Switch Sensor Interface IC Benefits Silicon MEMS BUS ICs • Fail safe read out of multiple safety interlock switches • Automotive Seat occupancy, Seat belt buckle, Airbag presence detection • Automotive Door lock position, Hood and Trunk latched detection • Industrial Security doors and machine guarding • Industrial pressure, strain gauge, … 2 wire analog sensors (ref. MLX90308, MLX90314) CMOS Imaging Applications Hall ICs • Benefits for Resistive switches The high current range (up to 40mA) allows contact cleaning. If, any contact aging occurs, the high measurement accuracy allows to track and even predict failures. • Benefits for 2-wire Hall effect switches The wide voltage and current range allows application of the MLX16305 with any 2-wire Hall effect sensor, including general purpose (3-wire) Hall effect switches like Melexis’ US5782 in a current biasing scheme. • Benefits for 2-wire analog sensor Industrial sensors and sensor interfaces having a 4 to 20 mA current range, like the MLX90308/90314, can be read out sequentially. Full Application schematic including resistive switch and general purpose hall switch in a 2-wire scheme 78L05 RF & RFID C1 10uF MLX16305 1 Sense3 Sense4 16 2 Sense2 Sense5 15 3 Sense1 Sense6 14 4 VSUP VSS 13 DIG1 5 ENABLE1 RREF 12 DIG2 6 MUX_SENSE1 MEAS_OUT 11 DIG3 7 MUX_SENSE2 VI_CTRL 10 DIG4 8 MUX_SENSE3 VREF C2 47nF Microcontroller VDD Rser To Interlock Switches Rpar Automotive ICs Application Schematics R2 820Ω R1 2.2kΩ 9 1 2 OUT VDD US5782 VSS 3 C3 10nF DIG5 ADC1 An 18 switch application requires 1ADC input and 7 digital IO’s Switches[1:6] Switches[7:12] Switches[13:18] 1 16 1 16 15 2 15 2 15 14 3 14 3 13 4 13 4 12 5 12 5 11 6 11 6 10 7 10 7 9 8 9 8 3 4 5 6 7 8 MLX16305 16 2 MLX16305 1 MLX16305 Sensor Interface Intelligent Drivers and Actuators VSS 14 13 12 11 10 9 4 Hall ICs IO1 IO[2..5] ADC IO6 IO7 Microcontroller Silicon MEMS CMOS Imaging Application Example with 2 wire Hall Switch This example shows the threshold voltages for a 2 wire Hall switch with currents IOFF=[5; 6.9]mA and ION=[12; 17]mA. Vref is taken from the 5V microcontroller supply regulator and Rref is set to 1kW. 1. 2. 3. 4. 5. 6. Short to Supply: Short between Wires: Open Wire : Switch current: IOFF: 0.43V < Switch current ION: 1.03V < Short to GND : VThreshold VThreshold VThreshold VThreshold VThreshold VThreshold > > < < < > 0.2V 0.2V 0.02V 0.65V 1.61V 4.5V Each value is applicable after setting the appropriate values on the digital IOs. BUS ICs Disclaimer: Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Melexis reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Melexis for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical lifesupport or life-sustaining equipment are specifically not recommended without additional processing by Melexis for each application. The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of Melexis’ rendering of technical or other services. © 2006 Melexis NV. All rights reserved. Email Europe and rest of the world: [email protected] Email USA : [email protected] For additional information go to our website at: Email Asia: [email protected]