Fully Integrated Proximity and Ambient Light Optical Sensor with 16-Bit Resolution

Aug. 3, 2012
Vishay Intertechnology, Inc. announced a new fully integrated proximity and ambient light optical sensor with the industry's lowest height of 0.8 mm.

Vishay Intertechnology, Inc. announced a new fully integrated proximity and ambient light optical sensor with the industry's lowest height of 0.8 mm. The VCNL4020 combines an IR emitter, a photo-pin-diode for proximity, an ambient light detector, a signal processing IC, and a 16-bit ADC in one small 4.8 mm x 2.3 mm x 0.8 mm rectangular leadless (LLP) package. The 3-in-1 sensor features an interrupt function, supports I²C bus communication interface, and greatly simplifies window and sensor placement in a wide variety of consumer and industrial applications.

For mobile devices such as smart phones, touch phones, PDAs, GPS units, and digital cameras, the new VCNL4020 saves power as a proximity sensor by turning off the display backlight when close to the user while using its integrated ambient light function for display/keypad adaptive brightness control. Containing all the circuitry needed for these applications in one device, the VCNL4020 eliminates the need for additional light barriers and optical alignment of the IR emitter and photo diode. While other devices with similar features use chip on PCB technology that results in package heights of 1.2 mm or greater, the VCNL4020 uses a proprietary technology that delivers the lowest height on the market. This gives design engineers greater flexibility in where and how they locate the sensor. For additional flexibility, the VCNL4020 can function at any depth or air gap below the glass window, unlike devices with 8-, 10-, and 12-bit resolutions that require depths or air gaps of 1.5 mm or less. Lower-resolution devices must also be placed away from other components on a costly and dedicated flexible circuit. The 16-bit resolution of the VCNL4020 allows it to be assembled on the main PCB near other components, ensures excellent cross talk immunity, and is especially important given that windows above the sensor absorb typically 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 it wakes up the microcontroller. This helps customers reduce their software effort and lower their power consumption by eliminating polling communication traffic between the sensor and microcontroller.

The ambient light photo-pin-diode built into the VCNL4020 offers sensitivity close to that of the human eye, with a 16-bit dynamic range for ambient light detection from 0.25 lux to 16 klux. The sensor offers 100 Hz and 120 Hz flicker noise rejection.

Featuring low standby current consumption of 1.5 µA, the device offers a supply voltage range of 2.5 V to 3.6 V and I²C bus voltage range from 1.7 V to 5 V. The sensor provides a Moisture Sensitivity Level (MSL) of 4 and operates over a temperature range of -25°C to + 85 °C. The VCNL4020 is compliant to RoHS Directive 2011/65/EU and WEEE 2002/96/EC, free of halogens, and compatible with lead (Pb)-free soldering.

Samples and production quantities of the new VCNL4020 are available now, with a lead time of eight weeks for large orders. Pricing for U.S. delivery only starts at $1.20 per piece in 1,800-piece (one reel) quantities. A VCNL4020 demo kit enabling quick and easy evaluation of the sensor in designers' applications can be requested.

Vishay Intertechnology
Part Number: VCNL4020


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