ATMEL T2525 User Manual
Features
• No External Components Except PIN Diode
• Supply-voltage Range: 4.5 V to 5.5 V
• Automatic Sensitivity Adaptation (AGC)
• Automatic Strong Signal Adaptation (ATC)
• Enhanced Immunity Against Ambient Light Disturbances
• Available for Carrier Frequencies between 30 kHz to 76 kHz; Adjusted by Zener Diode
Fusing
• TTL and CMOS Compatible
• Suitable Minimum Burst Length ³ 6 or 10 Pulses/Burst
Applications
• Audio Video Applications
• Home Appliances
• Remote Control Equipment
Description
The IC T2525 is a complete IR receiver for data communication developed and optimized for use in carrier-frequency-modulated transmission applications. Its function
can be described using the block diagram (see Figure 1). 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 f
input signal. The demodulator is used to convert the input burst signal into 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 condition (ambient light, modulated lamps etc.). Other special features are
used to adapt to the current application to secure best transmission quality. The
T2525 operates in a supply-voltage range of 4.5 V to 5.5 V.
which is equivalent to the chosen carrier frequency of the
0
IR Receiver
ASSP
T2525
Figure 1. Block Diagram
Carrier frequency f
Modulated IR signal
min 6/10 pulses
IN
0
Input
Oscillator
CGA and
filter
AGC/ATC and digital
GND
VS
control
Demodulator
OUT
Micro-
controller
Rev. 4657D–AUTO–11/03
Pin Configuration
Figure 2. Pinning SO8 and TSSOP8
Pin Description
Pin Symbol Function
1 VS Supply voltage
2 NC Not connected
3 OUT Data output
4 NC Not connected
5 IN Input PIN diode
6 GND Ground
7 NC Not connected
8 NC Not connected
VS
NC
OUT
NC
1
8
NC
2
7
NC
3
6
GND
4
5
IN
Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameters Symbol Value Unit
Supply voltage V
Supply current I
Input voltage V
Input DC current at V
= 5 V I
S
Output voltage V
Output current I
Operating temperature T
Storage temperature T
Power dissipation at T
= 25°C P
amb
S
S
IN
IN
O
O
amb
stg
tot
-0.3 to +6 V
3mA
-0.3 to V
S
V
0.75 mA
-0.3 to V
S
V
10 mA
-25 to +85 °C
-40 to +125 °C
30
mW
Thermal Resistance
Parameter Symbol Value Unit
Junction ambient SO8 R
Junction ambient TSSOP8 R
thJA
thJA
130 K/W
TBD K/W
2
T2525
4657D–AUTO–11/03
T2525
Electrical Characteristics
T
= 25°C, VS = 5 V unless otherwise specified.
amb
No. Parameters Test Conditions Pin Symbol Min. Typ. Max. Unit Type*
1 Supply
1.1 Supply-voltage range 1 V
1.2 Supply current I
= 0 1 I
IN
S
S
2Output
T
Internal pull-up
2.1
resistor
(1)
2.2 Output voltage low
2.3 Output voltage high 3,1 V
Output current
2.4
clamping
= 25°C;
amb
see Figure 9 on page 7
= 2 mA;
I
L
see Figure 9 on page 7
= 0;
R
2
see Figure 9 on page 7
1,3 R
3,6 V
3,6 I
PU
OL
OH
OCL
3 Input
3.1 Input DC current
Input DC current;
3.2
Figure 4 on page 5
IN
see Figure 9 on page 7
= 0; Vs = 5 V,
V
IN
T
= 25°C
amb
5I
5I
IN_DCMAX
IN_DCMAX
= 0;
V
Test signal:
see Figure 8 on page 7
VS = 5 V,
T
= 25°C,
Minimum detection
3.3
threshold current;
Figure 3 on page 5
amb
= 1 µA;
I
IN_DC
square pp,
burst N = 16,
f = f
; t
= 10 ms,
0
PER
3 I
Eemin
Figure 8 on page 7;
BER = 50
(2)
Test signal:
see Figure 8 on page 7
= 5 V,
V
Minimum detection
threshold current with
3.4
AC current disturbance
IIN_AC100 = 3 µA at
100 Hz
S
T
= 25°C,
amb
I
= 1 µA,
IN_DC
square pp,
burst N = 16,
f = f
; t
= 10 ms,
0
PER
3 I
Eemin
Figure 8 on page 7;
BER = 50%
(2)
*) Type means: A =100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Notes: 1. Depending on version, see “Ordering Information”
2. BER = Bit Error Rate; e.g., BER = 5% means that with P = 20 at the input pin 19...21 pulses can appear at the pin OUT
3. After transformation of input current into voltage
4.555.5V C
0.8 1.1 1.4 mA B
30/40 kW A
250 mV B
VS - 0.25 Vs V B
8mAB
-85 µA C
-530 -960 µA B
-520 pA B
-800 pA C
4657D–AUTO–11/03
3
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