The TBA2800 is an infrared preamplifier in a 14–Lead DIP type package and contains four main parts: the gain–controlled amplifier I, the amplifier II, the pulse–separating amplifier III, and the inverter IV.
The amplifier I has a wide dynamic range and thus ensures interference free operation, also at bright
ambient light, 50Hz modulated light originating from fluorescent lamps, or at intensive infrared light, e.g. produced by infrared sound transmission. It is also possible, to approach almost directly the remote–
control transmitter to the receiver without producing misfunction by overdriving the receiver. The amplifier II further amplifies the signal, and amplifier III separates the pulse–shaped intelligence signal from noise and other unwanted parts. The inverter IV provided additionally inverts the output signal available at Pin7 as negative pulse, and thus delivers positive output pulses at Pin8. If an additional resistor is inserted between Pin6 and GND, the noise–immunity is increased, but the input sensitivity
decreased. Pin10 serves as test pin and must not be connected. The capacitor connected from Pin2 to GND influences the automatic gain control of amplifier I contained in the TBA2800. A capacitance of less than 1µF will cause misfunction in the distance range of 0.2, to 2m.
14 pin DIP. Actual brand may vary from picture.