PTC PT2212

Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
DESCRIPTION
PT2212 is a remote control transmitter utilizing CMOS Technology specially designed for infrared
remote control applications. PT2212 can support up to 256 command codes and is functionally
compatible with TC9012. Pin assignments and application circuit are optimized for easy PCB Layout
and low cost advantage.
FEATURES
•
•
•
•
•
•
•
•
•
•
CMOS technology
Low power consumption
Least external components
Low voltage operation
Double key operation
Up to 32 function keys provided
Up to 8 system codes
Up to 256 command codes
High efficiency transmission
Transmission indication output pin provided
APPLICATIONS
•
•
•
•
•
•
Television
VCR
Video disc
CD player
AV controller
Audio equipment
PT2212 V1.1
-1-
May, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
BLOCK DIAGRAM
PT2212 V1.1
-2-
May, 2007
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
PIN CONFIGURATION
PIN DESCRIPTION
Symbol
I/O
KI0 ~ KI3
I
DOUT
O
VDD
NC
OSCO
OSCI
VSS
O
I
-
LMP
O
KO0 ~ KO7
SEL
O
I
PT2212 V1.1
Description
Key Matrix Input Pins
Built-in Pull-down Resistance
Remote Output Pin
The transmission pulse row modulated with carrier (38KHz duty 1/3)
is outputted. Large output current may be obtained for operating
infrared LED by means of driving base of NPN-Tr
Positive Power Supply
No Connection
Oscillator Output Pin.
Oscillator Input Pin
Negative Power Supply
Transmission Indication Output Pin.
This pin connects the transmission Indicator LED.
Key Matrix Output Pins
System Code Selection Pin
-3-
Pin No.
1~4
5
6
7
8
9
10
11
19 ~12
20
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
FUNCTION DESCRIPTION
TRANSMISSION CODE FORMAT
The PT2212 transmission code is composed a leader code, system code, and the data code. There
are 8-bit of system code (S0 to S7) and this 8-bit system code is outputted twice. Likewise, there are
8-bit of data code (D0 to D7), and the inversion data code is also transmitted. Please refer to the
diagram below for details.
The leader code is composed of a 4.5ms “High” and 4.5ms “Low”. The system code and the data code
are transmitted via a P.P.M. (Pulse Position Modulation) Method. With the system codes transmitted
twice and the data code sent with its inversion code, simultaneously, highly efficient operations can be
constructed.
The Bit “0” and “1” waveforms are given below:
Note: r=Tm, Tm=256/fosc=0.56ms
The leader code and the first bit of the inverted system code (S0) are transmitted when the key is
continuously pressed, thus reduction of the reception treating time and the power dissipation of the
infrared LED is possible. At this point, the leader code become very dominant that the average current
flow towards the infrared LED is reduced to 1.8% of the peak value leading to a highly efficient
transmission.
PT2212 V1.1
-4-
May, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
KEY INPUT OPERATION
A Key Input Operation may be considered legal or illegal depending on the key pressed. For key
interconnection, please refer to the application circuit diagram in the APPLICATION CIRCUIT
SECTION.
A pull-down resistor is already connected in the VSS Terminals of the Key Input Pins. A 4x8 Key Matrix
which may be constructed by connecting Key Inputs – KI0 to KI3 and Key Scan Outputs – KO0 to KO7.
When more than two keys are pressed simultaneously, the transmission is terminated by the
multi-depression preventive circuit function. For conditions regarding the double key operation, please
refer to the DOUBLE KEY OPERATION SECTION.
If a key has been continuously pressed for a period of 36ms, the system code and the data code are
read and transmitted once. For ON Chattering prevention, the data reading is NOT performed when
the key is pressed during the first 9ms.
DOUBLE KEY OPERATION
As stated earlier, double key operation is possible for the following key combinations:
K21 and K22
K21 and K23
K21 and K24
K25 and K26
K25 and K27
K25 and K28
If other key combinations are pressed other than those stated above, then it is considered illegal
because of the PT2212’s multiple depression preventive circuitry. However, it is possible to inhibit this
multiple depression preventive circuitry so that a double key operation may be performed, thereby a
transmission can occur. This condition is possible if the D5 of the Data Code is set to “1”. Because of
the order of priority, a transmission can only be made possible in this mode by pressing K22~K24
(K26~K28) 126ms after pressing K21 (K25). Please refer to the diagrams below.
DOUBLE KEY TRANSMISSION TIMING
PT2212 V1.1
-5-
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
DOUBLE KEY TRANSMISSION INHIBITION
PT2212 V1.1
-6-
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
DATA CODE
Key
K1
K2
K3
K4
K5
K6
K7
K8
K9
K10
K11
K12
K13
K14
K15
K16
K17
K18
K19
K20
K21
K22
K23
K24
K25
K26
K27
K28
K29
K30
K31
K32
PT2212 V1.1
KI0
*
Connection
KI1 KI2 KI3
*
KO
KO0
*
*
*
*
KO1
*
*
*
*
KO2
*
*
*
*
KO3
*
*
*
*
KO4
*
*
*
*
KO5
*
*
*
*
KO6
*
*
*
*
KO7
*
*
D0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
-7-
D1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
D2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Data Code
D3 D4 D5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
1
1
0
1
1
0
1
1
0
1
1
0
1
1
0
1
1
0
1
1
0
1
1
0
D6
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
D7
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
May, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
DATA CODE FOR DOUBLE KEY OPERATION
Prior Key
K21
K25
Combined Key
K22
K23
K24
K26
K27
K28
D0
1
0
1
1
0
1
D1
0
1
1
0
1
1
D2
1
1
1
0
0
0
D3
0
0
0
1
1
1
D4
1
1
1
1
1
1
D5
1
1
1
1
1
1
D6
0
0
0
0
0
0
D7
0
0
0
0
0
0
KEY MATRIX
The following diagram illustrated the PT2212 Key Matrix.
PT2212 V1.1
-8-
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
REMOTE OUTPUT WAVEFORM
The transmission signal is outputted after the pulse is modulated with 37.9KHz 1/3 of the 12-divided
duty at 455KHz.
PT2212 V1.1
-9-
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
OSCILLATION
An oscillation circuit may be constructed by connecting a ceramic oscillator to the Oscillator Pins,
namely: OSCO and OSCI. The oscillation frequency is 455KHz. When operation is in a stand-by mode,
the oscillation is also normally stopped, thus, minimizing power consumption.
When the key switch is pressed, the oscillation starts and the operation begins. When the key is
released, the stand-by mode will again be initiated after the completion of the operation. Please refer to
the diagram below.
When fosc=455KHz, the oscillation output is divided into 12 parts and the modulation carrier frequency
is 37.9 ~ 39.2KHz and 1/3 duty. The 455KHz oscillation is divided into 256 parts and the system
fundamental clock is 1.78KHz. The inter-relation between modulation carrier (fc) and the system clock
(Tm) with respect to the oscillation frequency (fosc) is given in the equations below.
MODULATION CARRIER, fc = (1/12) fosc (Duty: 1/3)
SYSTEM CLOCK, Tm= 256/fosc
As stated earlier, 455KHz oscillation, the signal is outputted after the pulse is modulated with a
37.9KHz, 1/3 of the duty 12-divided by the carrier generation circuit. Please refer to the carrier
waveform diagram below.
PT2212 V1.1
- 10 -
May, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
It is highly recommended that the following notes must be strictly observed in the preparation of the
reception software:
• System Code
The 8-bit system code is transmitted twice. Therefore, you must decode both codes to be
identical.
• Data Code
The 8-bit data code is transmitted simultaneously with its inversion code. Therefore, you must
decode the data code and its inversion code and never fail to check their integrity.
SYSTEM CODE LATCH CIRCUIT
There are 8 kinds of system code that can be selected by wiring the SEL pin to any one of the output
pins-KO0 ~ KO7. The fourth bit of the system code (S3) is set to “1”, S4 to S7 bits are “0”. Please refer
to the table and diagram below.
KO connected to SEL
KO0
KO1
KO2
KO3
KO4
KO5
KO6
KO7
System Code (S2 S1 S0)
000
001
010
011
100
101
110
111
Following is the system code selection diagram.
Notes:
1. S0, S1, S2 = 010
2. System Code = 01010000 (S0 to S7)
PT2212 V1.1
- 11 -
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
ABSOLUTE MAXIMUM RATING
(Unless otherwise specified, Ta=25℃)
Parameter
Symbol
Power supply voltage
VDD
Input voltage
VIN
Operating temperature
Topr
Storage temperature
Tstg
Rating
-0.3 ~ 5.0
VSS-0.3 ~ VDD+0.3
-40 ~ +85
-65 ~ +150
Unit
V
V
℃
℃
ELECTRICAL CHARACTERISTIC
(Unless otherwise specified, VDD=3.0V, Ta=25℃)
Parameter
Symbol
Test Condition
Operating power supply
VDD
All Functions
VDD=3V
Oscillation frequency
fosc
C=100pF
Operating power supply
fosc=455KHz
IDD
current
VDD=3V
VDD=3V
Stand-by current
ISB
fosc=stop
High level input voltage
VIH(KI)
VDD=3V
Low level input voltage
VIL(KI)
VDD=3V
Pull down resistance
Ron (KI) VDD=3V
IOH
VOH=1.5V
High level output current
(DOUT)
VDD=3V
VOL=1.5V
Low level output current
IOL (LMP)
VDD=3V
PT2212 V1.1
- 12 -
Min.
2.0
Typ.
-
Max.
4.0
Unit
V
400
455
600
KHz
-
-
1
mA
-
-
1
uA
0.7VDD
0
100
300
VDD
0.3VDD
500
V
V
KΩ
-10
-
-
mA
5
-
-
mA
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
APPLICATION CIRCUIT
PT2212 V1.1
- 13 -
May, 2007
Tel: 886-2-66296288
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URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
ORDER INFORMATION
Valid Part Number
PT2212
PT2212 V1.1
Package Type
20 Pins, SOP, 300mil
- 14 -
Top Code
PT2212
May, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
PACKAGE INFORMATION
20 PINS, SOP, 300MIL
Symbol
A
A1
B
C
D
E
e
H
h
L
α
PT2212 V1.1
Min.
2.35
0.10
0.33
0.23
12.60
7.40
10.00
0.25
0.40
0°
Nom.
1.27 bsc.
- 15 -
Max.
2.65
0.30
0.51
0.32
13.00
7.60
10.65
0.75
1.27
8°
May, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Infrared Remote Control Transmitter
PT2212
Notes:
1. Dimensioning and tolerancing per ANSI Y14.5M-1982.
2. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold Flash, protrusion or gate
burrs shall not exceed 0.15 mm (0.006 in) per side.
3. Dimension “E” does not include interlead flash or protrusions. Interlead flash or protrusions shall not
exceed 0.25 mm (0.010 in) per side.
4. The chamfer on the body is optional. It is not present, a visual index feature must be located within
the crosshatched area.
5. “L” is the length of the terminal for soldering to a substrate.
6. N is the number of the terminal positions (N=20)
7. The lead width “B” as measured 0.36 mm (0.014 in) or greater above the seating plane, shall not
exceed a maximum value of 0.61 mm (0.24 in).
8. Controlling dimension: MILLIMETER.
9. Refer to JEDEC MS-013, Variation AC.
JEDEC is the trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION.
PT2212 V1.1
- 16 -
May, 2007