Vishay has introduced a fully integrated proximity and ambient-light optical sensor with an operating temperature range up to 105°C, suitable for use in harsh automotive and other applications.
The VCNL4020X01 combines an IR emitter, a photo-diode for proximity sensing, an ambient light detector, a signal-processing IC and a 16-bit ADC, all in a 4.8mm x 2.3mm x 0.8mm leadless package.
By integrating the emitter and sensor elements into a single small device, the VCNL4020X01 greatly simplifies window and sensor placement in automotive, consumer and industrial applications.
When used in automotive dashboard displays and in mobile devices as a proximity sensor, the Vishay Semiconductors VCNL4020X01 saves power, since it alerts the system to turn off the display backlight until a user is detected. At the same time, its integrated ambient-light function supports adaptive brightness control in displays and keypads, as well as rear-view mirror dimming. Containing all the circuitry needed for these applications in one device, the VCNL4020X01 eliminates the need for additional light barriers and for optical alignment of the IR emitter and photo-diode.
The VCNL4020X01 can function at any depth below the glass, unlike devices with 8-, 10- or 12-bit resolution, which require a depth of 1.5mm or less. Lower-resolution devices must also be placed away from other components on a costly flexible circuit. By contrast, the 16-bit resolution of the VCNL4020X01 allows it to be assembled on the main PCB near other components. It also ensures excellent cross-talk immunity.
The VCNL4020X01’s Interrupt function enables the sensor to work independently until a pre-defined proximity or ambient light event occurs, at which point it wakes up the microcontroller. This helps designers to lower power consumption by eliminating polling communication traffic between the sensor and microcontroller.
While other products only achieve object detection up to 100mm, the VCNL4020X01 provides a programmable LED drive current from 10mA to 200mA in 10mA steps, allowing for detection distances up to 200mm.
In proximity mode, the device offers excellent ambient-light suppression by modulating the infra-red signal. The emitter wavelength peaks at 890nm and has no visible red tail, unlike many devices from other manufacturers. The ambient light photo-diode in the VCNL4020X01 offers sensitivity close to that of the human eye, with dynamic range from 0.25lux to 16klux.
- Proximity sensing
- Presence detection
- Display/keypad contrast and brightness control
- Dimming control in rear-view mirrors
- AEC-Q101 qualified
- Supply voltage range: 2.5V to 3.6V
- 1.5μA stand-by current
- Rejects 100hz and 120hz flicker noise
- I2C interface