ATA2525 Datasheet, PDF (1/12 Pages) ATMEL Corporation – IR Receiver ASSP

Features
• No External Components Except PIN Diode
• Supply-voltage Range: 4.5V to 5.5V
• High Sensitivity Due to Automatic Sensitivity Adaption (AGC) and Automatic Strong
Signal Adaption (ATC)
• High Immunity Against Disturbances from Daylight and Lamps
• Small Size and Innovative Pad Layout
• Available for Carrier Frequencies between 33 kHz to 40 kHz; Adjusted
by Zener Diode Fusing
• TTL and CMOS Compatible
• Suitable Minimum Burst Length ≥ 10 Pulses/Burst
Applications
• Home Entertainment Applications
• Home Appliances
• Remote Control Equipment
IR Receiver
ASSP
ATA2525
1. Description
The IC ATA2525 is a complete IR receiver for data communication that was devel-
oped 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 flexibil-
ity for assembly of IR receiver modules. The ATA2525 is available with standard
carrier frequencies (33, 36, 37, 38, 40 kHz) and 3 different noise suppression regula-
tion types (standard, lamp, noise) covering requirements of different high-volume
remote control solutions (please refer to selection guide available for
ATA2525/ATA2526). The ATA2525 operates in a supply voltage range of 4.5V to
5.5V.
The function of ATA2525 can be described using the block diagram (see 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 to convert the
input burst signal into a digital envelope output pulse and to evaluate the signal infor-
mation 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 condition (ambient light, modulated lamps etc.).
Other special features are used to adapt to the current application to secure best
transmission quality.
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