T2526_09 Datasheet, PDF (1/14 Pages) ATMEL Corporation – Low-voltage IR Receiver ASSP

Features
• No External Components Except PIN Diode
• Supply-voltage Range: 2.7V to 5.5V
• Highest Sensitivity Due to Automatic Sensitivity Adaption (AGC) and Automatic Strong
Signal Adaption (ATC)
• Automatic Supply Voltage Adaptation
• Highest Immunity against Disturbances from Daylight and Lamps
• Available for Carrier Frequencies between 30 kHz to 76 kHz; adjusted by Zener-Diode
Fusing ±2.5%
• TTL and CMOS Compatible
Applications
• Home Entertainment Applications (Audio/Video)
• Home Appliances
• Remote Control Equipment
1. Description
The IC T2526 is a complete IR receiver for data communication developed and opti-
mized for use in carrier-frequency-modulated transmission applications. The IC offers
highest sensitivity as well as highest suppression of noise from daylight and lamps.
The T2526 is available with broadest range of frequencies (30, 33, 36, 37, 38, 40, 44,
56, 76 kHz) and 5 different noise suppression regulation types (standard, lamp, noise,
short burst, data rate) covering requirements of high-end remote control solutions
(please refer to selection guide available for T2525/T2526). The T2526 operates in a
supply voltage range of 2.7V to 5.5V.
The function of the T2526 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.
Low-voltage
IR Receiver
ASSP
T2526
4597H–AUTO–09/09