Vishay releases fully integrated proximity and ambient light optical sensors

     Vishay Intertechnology has announced the launch of its new fully integrated proximity and ambient light optical sensor, the VCNL4020, with the industry's lowest height of 0.8mm. The device combines an infrared emitter, a photodiode for proximity measurement, an ambient light detector, a signal conditioning IC, and a 16-bit ADC all in a small 4.8mm x 2.3mm x 0.8mm rectangular leadless (LLP) package. The 3-in-1 sensor has an interrupt function and supports an I2C bus communication interface, greatly simplifying the placement of Windows and sensors in a wide variety of consumer and industrial applications.

     For mobile devices such as smartphones, touchscreen phones, PDAs, GPS units and digital cameras, the new VCNL4020 can be used as a proximity sensor to turn off the display backlight when an object is close to the user, while using its integrated ambient light function to adaptive control the brightness of the display/keyboard to save energy. The VCNL4020 puts all the circuits needed for these applications in one device, requiring no additional grating or alignment of the infrared emitter and photodiode in the optical path.

     While other devices with similar characteristics use chip packages on printed circuit boards that are 1.2mm thick or thicker, the VCNL4020 uses exclusive technology and is the thinest product on the market. This gives designers greater flexibility in deciding where and how to place sensors. More flexible, the VCNL4020 can operate at any depth or air gap under the glass window, unlike other 8 -, 10 - or 16-bit devices that require a depth or air gap of no more than 1.5mm or less. On expensive specialized flexible circuit boards, lower resolution devices must be kept at a distance from other components. The 16-bit resolution VCNL4020 can be installed near other components on the main PCB and is very resistant to crosstalk, which is especially important when the window above the sensor typically absorbs 90% of the infrared emission.

     The VCNL4020's interrupt function enables the sensor to work independently until a predefined proximity or ambient light event occurs, and then wakes up the microcontroller. This helps consumers reduce their software overhead and reduce power consumption by reducing polling traffic between sensors and microcontrollers.

     While other products can only detect objects within 100mm, the VCNL4020 makes the detection distance up to 200mm by increasing the 10mA to 200mA programmable LED drive current in 10mA increments. To increase the detection range of the proximity sensor, the VCNL4020 also includes an integrated external transmitter driver. Tests with two external transmitters show that the detection range can reach 1m. The device modulates the infrared signal and has excellent ability to suppress the ambient light. The transmitter has a peak wavelength of 892nm and no visible "red tail," unlike many devices from other manufacturers.

     The ambient photodiode is built into the VCNL4020, the sensitive characteristics are close to the human eye, and the 16-bit dynamic range enables the detection range of ambient light to reach 0.25lux ~ 16klux. The sensor is not affected by 100Hz and 120Hz stroboscopic noise.

     The standby current of the device is only 1.5µA, the supply voltage is 2.5V to 3.6V, and the I2C bus voltage is 1.7V to 5V. The humidity sensitivity of the sensor is 3, and the operating temperature is -25℃ ~ +85℃. VCNL4020 complies with RoHS Directive 2011/65/EU and WEEE 2002/96/EC, is halogen-free and can be welded lead-free.