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
IR Receiver
ASSP
T2525
Description
The IC T2525 is a complete IR receiver for data communication developed and opti-
mized 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
0
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 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 environ-
mental 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.
Figure 1.
Block Diagram
VS
IN
Input
CGA and
filter
Demodulator
OUT
Micro-
controller
Oscillator
Carrier frequency f
0
AGC/ATC and digital
control
Modulated IR signal
min 6/10 pulses
GND
Rev. 4657D–AUTO–11/03
Pin Configuration
Figure 2.
Pinning SO8 and TSSOP8
VS
NC
OUT
NC
1
2
3
4
8
7
6
5
NC
NC
GND
IN
Pin Description
Pin
1
2
3
4
5
6
7
8
Symbol
VS
NC
OUT
NC
IN
GND
NC
NC
Function
Supply voltage
Not connected
Data output
Not connected
Input PIN diode
Ground
Not connected
Not connected
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
Supply voltage
Supply current
Input voltage
Input DC current at V
S
= 5 V
Output voltage
Output current
Operating temperature
Storage temperature
Power dissipation at T
amb
= 25°C
Symbol
V
S
I
S
V
IN
I
IN
V
O
I
O
T
amb
T
stg
P
tot
Value
-0.3 to +6
3
-0.3 to V
S
0.75
-0.3 to V
S
10
-25 to +85
-40 to +125
30
Unit
V
mA
V
mA
V
mA
°C
°C
mW
Thermal Resistance
Parameter
Junction ambient SO8
Junction ambient TSSOP8
Symbol
R
thJA
R
thJA
Value
130
TBD
Unit
K/W
K/W
2
T2525
4657D–AUTO–11/03
T2525
Electrical Characteristics
T
amb
= 25°C, V
S
= 5
V unless otherwise specified.
No.
1
1.1
1.2
2
2.1
2.2
2.3
2.4
3
3.1
3.2
Parameters
Supply
Supply-voltage range
Supply current
Output
Internal pull-up
resistor
(1)
Output voltage low
Output voltage high
Output current
clamping
Input
Input DC current
Input DC current;
Figure 4 on page 5
V
IN
= 0;
see Figure 9 on page 7
V
IN
= 0; V
s
= 5 V,
T
amb
= 25°C
Test signal:
see Figure 8 on page 7
V
S
= 5 V,
T
amb
= 25°C,
I
IN_DC
= 1 µA;
square pp,
burst N = 16,
f = f
0
; t
PER
= 10 ms,
Figure 8 on page 7;
BER = 50
(2)
5
5
I
IN_DCMAX
I
IN_DCMAX
-85
-530
-960
µA
µA
C
B
R
2
= 0;
see Figure 9 on page 7
T
amb
= 25°C;
see Figure 9 on page 7
I
L
= 2 mA;
see Figure 9 on page 7
1,3
3,6
3,1
3,6
R
PU
V
OL
V
OH
I
OCL
V
S
- 0.25
8
30/40
250
Vs
kW
mV
V
mA
A
B
B
B
I
IN
= 0
1
1
V
S
I
S
4.5
0.8
5
1.1
5.5
1.4
V
mA
C
B
Test Conditions
Pin
Symbol
Min.
Typ.
Max.
Unit
Type*
3.3
Minimum detection
threshold current;
Figure 3 on page 5
3
I
Eemin
-520
pA
B
3.4
Test signal:
see Figure 8 on page 7
V
S
= 5 V,
Minimum detection
T
amb
= 25°C,
threshold current with
I
IN_DC
= 1 µA,
AC current disturbance square pp,
IIN_AC100 = 3 µA at
burst N = 16,
100 Hz
f = f
0
; t
PER
= 10 ms,
Figure 8 on page 7;
BER = 50%
(2)
3
I
Eemin
-800
pA
C
*) 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
3
4657D–AUTO–11/03
Electrical Characteristics (Continued)
T
amb
= 25°C, V
S
= 5
V unless otherwise specified.
No.
Parameters
Test Conditions
Test signal:
see Figure 8 on page 7
V
S
= 5 V, T
amb
= 25°C,
I
IN_DC
= 1 µA;
square pp,
burst N = 16,
f = f
0
; t
PER
= 10 ms,
Figure 8 on page 7;
BER = 5%
(2)
Pin
Symbol
Min.
Typ.
Max.
Unit
Type*
3.5
Maximum detection
threshold current with
V
IN
> 0V
3
I
Eemax
-400
µA
D
4
4.1
4.2
4.3
4.4
4.5
Controlled Amplifier and Filter
Maximum value of
variable gain (CGA)
Minimum value of
variable gain (CGA)
Total internal
amplification
(3)
Center frequency fusing
V
S
= 5 V, T
amb
= 25°C
accuracy of bandpass
Overall accuracy center
frequency of bandpass
BPF bandwidth:
type N0 - N3
BPF bandwidth:
type N6, N7
-3 dB; f
0
= 38 kHz; see
Figure 6 on page 6
-3 dB; f
0
= 38 kHz
Figure 6 on page 6
G
VARMAX
G
VARMIN
G
MAX
f
0_FUSE
f
0
B
B
-3
-6.7
51
-5
71
f
0
f
0
3.5
5.4
+3
+4.1
dB
dB
dB
%
%
kHz
kHz
D
D
D
A
C
C
C
4.6
*) 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
ESD
Reliability
All pins
Þ
2000V HBM; 200V MM, MIL-STD-883C, Method 3015.7
Electrical qualification (1000h) in molded SO8 plastic package
4
T2525
4657D–AUTO–11/03
T2525
Typical Electrical Curves at T
amb
= 25°C
Figure 3.
I
Eemin
versus I
IN_DC
, V
S
= 5 V
Figure 4.
V
IN
versus I
IN_DC
, V
S
= 5 V
Figure 5.
Data Transmission Rate, V
S
= 5 V
5
4657D–AUTO–11/03
嵌入式系统
