The IC ATA2526 is a complete IR receiver for data communication developed and optimized for use in carrier-frequency-modulated transmission applications. The IC combines small size with high sensitivity as well as high suppression of noise from daylight and lamps. An innovative and patented pad layout offers unique flexibility for assembly of IR receiver modules. The ATA2526 is available with standard frequencies (33, 36, 37, 38, 40, 56 kHz) and 3 different noise suppression regulation types (standard, lamp, short burst) covering requirements of different high-volume remote control solutions (please refer to selection guide available for ATA2525/ATA2526). The ATA2526 operates in a supply voltage range of 2.7V to 5.5V. The function of the ATA2526 can be described using the block diagram of Figure 1-1 on page 2. The input stage meets two main functions. First it provides a suitable bias voltage for the PIN diode. Secondly the pulsed photo-current signals are transformed into a voltage by a special circuit which is optimized for low noise applications. After amplification by a Controlled Gain Amplifier (CGA) the signals have to pass a tuned integrated narrow bandpass filter with a center frequency f0 which is equivalent to the chosen carrier frequency of the input signal The demodulator is used first to convert the input burst signal to a digital envelope output pulse and to evaluate the signal information quality, i.e., unwanted pulses will be suppressed at the output pin. All this is done by means of an integrated dynamic feedback circuit which varies the gain as a function of the present environmental conditions (ambient light, modulated lamps etc.). Other special features are used to adapt to the current application to secure best transmission quality.