MLX75308 Rainlight Sensor Interface Melexis
The MLX75308 is a sensor interface that is dedicated to rain and light measurement, with two independent linear rain measurement channels and three logarithmic ambient channels. The circuit performs analog to digital conversion on photodiode current and transmits the data as two separate values – representing rain and sun signals – to an MCU, via a four-wire SPI bus that permits bi-directional communication.
Offering a superior level of performance and feature size over competing solutions, the MLX75308 is a highly versatile system component, with a large dynamic input range and output range. The output range can support LED currents up to 1A. This large dynamic range facilitates the use of a wide variety of photodiodes and windscreen types, suiting the part to automotive customers that desire a ‘one system fits all’ solution.
MLX75308 Features and Benefits
* Designed specifically to provide signal interface functions in the highly demanding RainLight module
* Offers a large and programmable dynamic range, allowing the part to cater to a wide range of input signals
* Offers a flexible and versatile digital SPI interface with large programmability and easy to use 16bit ADC readout.
* Has internal compensation for both large sunlight effects (static & dynamic) and for parasitic 2nd order effects of low-cost photodiodes(PDs). Both rain and sun signals are measured and compensated for at a 16bit level
* Includes an internal pre-driver to facilitate a large dynamic range, while external FETs allow for intense current peaks to maximize SNR and allow for the use of low cost PDs.
* Incorporates several diagnostic and internal watchdog features that enable system designers to design a fail-safe RLS system.
* Comes with 2 rain channels and 3 ambient channels, allowing the RLS system architect to connect to any PD required for best system performance or lowest cost.
* With the 3.3V power supply, sleep and standby modes, the MLX75308 offers an RLS system maximum flexibility, with low-power modes for different car-models.
* Comes in a small QFN4x4 leadless package with minimal footprint, external components and CU overhead for an RLS application.
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27 January 2012
