Ambient light sensor saves space in backlight dimming
Vishay Intertechnology has introduced a new high-accuracy digital ambient light sensor for flat-panel televisions and consumer handheld devices. The VEML7700 combines a photo-diode, low-noise amplifier and 16-bit ADC in a miniature, transparent surface-mount package measuring 6.8x3.0x2.35mm. The sensor adopts Filtron technology and supports an I²C bus interface for simple operation.
The VEML7700 is designed for backlight dimming and optical switching for consumer products, in addition to power on / off for industrial lighting systems. With its compact size and mounting flexibility as a side- or top-view device, the sensor allows designers to save space in compact TVs, CCTV cameras, smartphones, PDAs and GPS units, while providing flexibility in where and how they place the device. When used in conjunction with Vishay IR receivers such as the TSOP772, the VEML7700's side-view package offering the same dimensions and optical axis height greatly simplifies window designs.
Filtron technology enables ambient light spectral sensitivity close to that of the human eye, while the sensor's adoption of O-Trim technology provides an output tolerance under 10 %. The device offers detection from 0 to 167klx and resolution down to 0.005lx/ct, allowing for operation in applications with low-transmittance (dark) lens designs. The VEML7700 provides 100 and 120Hz flicker noise rejection and excellent temperature compensation from -25 to +85°C. The device offers low power consumption down to just 2μA in operating mode and 0.5μA in shutdown mode.
The VEML7700's supply voltage range is from 2.5 to 3.6V, while its I²C bus voltage range is from 1.7 to 3.6V. Offered in a lead-free, 4-pin molded package, the device is RoHS-compliant, halogen-free and Vishay Green.
Samples and production quantities of the new ambient light sensor are available now, with lead times of eight weeks for large orders.