Elmos E527.04 & E527.05

The RLT IC (Rain Light Tunnel Sensor) is intended for controlling an optical sensor unit in automotive wiping systems. 

The IC has two embedded LED drivers, which can be controlled with up to 40mA. These currents are perfectly adequate for reliable rain detection below the power consumption of other infrared-based solutions.

A special, high-sensitivity input stage allows the processing of a diode input signal without total reflection of the transmit signal, which ensures reliable detection of rain, water droplets and condensed precipitation. By eliminating the total reflection, smaller sensor form factors are possible in order to save space or extend the range of functions.

Thanks to the HALIOS®- Sigma Delta measurement, the system achieves a very high degree of robustness against environmental influences, such as sunlight, any type of flickering light, aging and dirt. It also offers the best sensitivity available in the market for improved rain classification. The IC has 4 additional input channels for logarithmically amplified ambient light measurements. Communication via a 3-wire or 4-wire SPI interface enables fast and flexible transmission.

Due to the integration density and the very high robustness, only a few external components are necessary. This lowers the cost of the overall system while maintaining high performance.

The E527.04 evaluation is available from Avnet Silica. Contact your local office.

Features & benefits

• Front end optical rain sensor signal processor
• Four input channels for ambient light measurements
• High sensitivity, no total reflection needed
• Very high robustness against ambient influences like sun light, aging and dirt
• Two embedded LED drivers, driving up to 40mA
• Provides a rain drop signal via the WS pin
• SPI interface
• Temperature sensor
• Extensive diagnosis during operation
• Low bill of materials due to few external components
• AEC-Q100 qualification
• EV-KIT AVAILABLE

Applications

• Optical rain sensing to control automotive wiping systems or industrial camera and window systems
• Ambient light measurements to control
• Headlights / lights
• Head-up displays 
• Air conditioning
• Pollution sensor

Block diagram