U2538B Datasheet, PDF (1/9 Pages) ATMEL Corporation – IR RECEIVER FOR DATA COMMUNICATION

Features
• Few External Components
• Low Power Consumption
• Microcomputer Compatible
• Insensitive to Ambient Light and Other Continuous Interferences
Applications
• Keyless Entry Systems
• Remote Control
• Wireless Data Transfer up to 4 kbit/s
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. Block Diagram with Typical Circuit
V_S
IR Receiver for
Data
Communication
U2538B
U2538B
Input
Amplifier
and filter
Detector
mC
Modulated IR signal
carrier frequency 20 to 60 kHz
minimum 6 pulses/burst
AGC/ATC
Rev. 4717A–IRRC–05/03
1