Features

Applications

1.

Description

The IC U2538B is a complete IR receiver for data communication. The useful input

signals are separated by a special input circuit and amplified by a gain-controlled

amplifier. The bandpass filter suppresses the off-band signals. The signal detector,

consisting of a demodulator, an integrator and a Schmitt trigger, forms the input signal

to an output pulse that can be interfaced to a microcomputer. The AGC and the ATC

circuit control the receiver's sensitivity, making it insensitive to ambient light sources.

Figure 1-1.

Block Diagram with Typical Circuit

Amplifier

and filter

Detector

Input

AGC/ATC

V

S

U2538B

µC

Modulated IR signal

carrier frequency 20 to 60 kHz

minimum 6 pulses/burst

IR Receiver for

Data

Communication

U2538B

Rev. 4717B–IRRC–09/05