Integrated colour LTV (light to voltage) sensors combine a photodiode, colour filter and transimpedance amplifier, whose output is then processed by an ADC. The TAOS solution requires fewer components, saves board space and reduces assembly cost over a discrete photodiode approach - plus sensitive analog circuitry is integrated on-chip which improves the noise immunity. Colour LTV devices are ideal for colorimetry, printing process control, display colour correction, and selectively ambient light detection or rejection.
The new TCS3771 combines colour sensing and proximity detection.
Integrated colour LTF (light-to-frequency) converters provide RGB colour sensing via a photodiode grid consisting of 16 groups of 4 elements each. The output for each colour is a square wave with frequency directly proportional to the intensity of the selected colour. Each group consists of red, green, blue and clear, and the digital colour information is input directly to a processor. The TAOS LTF approach eliminates circuitry since transimpedance amplifiers and analog-to-digital converters are no longer needed. The sensor can also be located remotely from the processor with no loss of noise immunity. Application examples include portable systems where space is critical.
Download application notes from the Application tab.