Photo-integrated circuits designed to accurately detect the proximity of an object in optical systems are available from Hamamatsu Corp. Suitable for use in robotics and high-speed optical switches, the S8030 and S8064 feature a photodiode, LED drive circuitry and a signal processing circuit in a subminiature plastic package. The devices, which can be used with an infrared LED and light-emitting/receiving lenses, incorporate a dual photodiode with a 0.7 x 0.5-mm active area per channel and a control/detection circuit. The company says the "visible light cut" housing and synchronous optical detector assure measurement accuracy and make the integrated circuits immune to background light. Typical specifications include a peak sensitivity wavelength of 850 nm, photosensitivity of 0.3 A/W, operation supply voltage of 5 V and an operating temperature range of -20 to +70 °C.