Please explain the block diagram of tsop1738 including the details that how automatic gain control and band pass filter usage in it

TSOP 1738 is a member of the IR remote control receiver series. This module consists of an IR sensor PIN-diode and amp, which are integrated into a single package. Exit the TSOP is active low and this gives +5 off. When infrared waves from a source with the Central frequency kHz, falling to 38, its output becomes low.

Light coming from the Sun, fluorescent lamps, etc, may violate it and lead to undesirable output, even when the source does not send IR signals. bandpass filter, step integrator and automatic gain control are used to suppress the interference.

Module TSOP has a built-in control circuit to amplify the coded pulses of IR transmitter signal is generated when the PIN photodiode receives signals. This input signal using automatic gain control (AGC). For the range of inputs, the output is fed back to the ARU in order to adjust the gain up to the appropriate level. AGC signal enters the bandpass filter for filtering out unwanted frequencies. After this signal is sent to the demodulator, and a demodulated output triggers the NPN transistor. The collector of the output transistor turns on the output module 3 the TSOP.
Members of the TSOP17xx series are sensitive to different central frequencies of infrared spectrum. For example TSOP1738 is sensitive to 38 kHz, while the TSOP1740 up to 40 kHz Center frequencies.