三合微科股½有限公司
S
AM
H
OP
Microelectronics Corp.
SM5221-001/002
32 KEYS ENCODER
GENERAL DESCRIPTION
The SM5221-001/002 is an infrared remote
control encoder LSI utilizing CMOS
technology. The transmission code
consists of "leader pulse", "16 bit customer
code", and "16 bit data code". Using
Micro-processors for decoder, various
applications can be realized.
FEATURES
* Low voltage operation ...... VDD=2.0 to 3.3V
* Low power consumption ...... IDD < 1
μ
A at
standby mode
* 32 function keys and 3 double action keys
* 64 + 6 function codes are available.
(Using SEL terminal)
* 65536 customer codes can be selected.
(Using external R, Diode-SM5024A or internal
MASK ROM-SM5024B)
* 20pin SOP or DIP
APPLICATIONS
* Audio Remote Control
* Video Remote Control
* Consumer Product Remote Control
PIN ASSIGNMENTS (TOP VIEW)
KI0
KI1
KI2
KI3
Dout
V
DD
SEL
OSCO
OSCI
V
SS
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
CODE
KI/O0
KI/O1
KI/O2
KI/O3
KI/O4
KI/O5
KI/O6
KI/O7
LED
KI0
KI1
KI2
KI3
Dout
V
DD
SEL
OSCO
OSCI
V
SS
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
CODE
KI/O0
KI/O1
KI/O2
KI/O3
KI/O4
KI/O5
KI/O6
KI/O7
LED
20 PIN DIP IN 300MIL
20 PIN SOP IN 300MIL
Page 1
V.2.0 Mar 8,2002
三合微科股½有限公司
S
AM
H
OP
Microelectronics Corp.
SM5221-001/002
32 KEYS ENCODER
PIN DESCRIPTION
No. Pin Name I / O
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
KI0
KI1
KI2
KI3
DOUT
VDD
SEL
OSCO
OSCI
VSS
LED
KI/O7
KI/O6
KI/O5
KI/O4
KI/O3
KI/O2
KI/O1
KI/O0
CODE
I
I
I
I
O
POWER
I
O
I
POWER
O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
Function
Scan Key Input 0
With Pull Low
Scan Key Input 1
With Pull Low
Scan Key Input 2
With Pull Low
Scan Key Input 3
With Pull Low
Remote Output
Postive Power
Supply
Data Select
Oscillator Output
Oscillator Input
Negative Power
Supply (substrate)
Indicator For
Tramsmission
Key Scan 7
Key Scan 6
Key Scan 5
Key Scan 4
Key Scan 3
Key Scan 2
Key Scan 1
Key Scan 0
Customer Code
Select Input
Pin Name No.
KI0
KI1
KI2
KI3
KI/O0
KI/O1
KI/O2
KI/O3
KI/O4
KI/O5
KI/O6
KI/O7
DOUT
SEL
LED
CODE
OSCO
OSCI
VDD
VSS
1
2
3
4
19
18
17
16
15
14
13
12
5
7
11
20
8
9
6
10
I/O
I
I
I
I
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
O
I
O
I/O
O
I
POWER
Function
Scan Key Input 0
With Pull Low
Scan Key Input 1
With Pull Low
Scan Key Input 2
With Pull Low
Scan Key Input 3
With Pull Low
Key Scan 0
Key Scan 1
Key Scan 2
Key Scan 3
Key Scan 4
Key Scan 5
Key Scan 6
Key Scan 7
Remote Output
Data Select
Indicator For
Tramsmission
Customer Code
Select Input
Oscillator Output
Oscillator Input
Postive Power
Supply
Negative Power
POWER
Supply (substrate)
Page 2
V.2.0 Mar 8,2002
三合微科股½有限公司
S
AM
H
OP
Microelectronics Corp.
SM5221-001/002
32 KEYS ENCODER
BLOCK DIAGRAM
OSCI
OSCO
V
DD
Vss
OSC CIRCUIT
KI
0
OUTPUT
KI
1
KEY INPUT SCAN
CIRCUIT
TIMING GENERATION & CONTROL
CIRCUIT
CONTROL
CIRCUIT
DOUT
LED
CODE GENERATION CIRCUIT
KI
2
CODE
KI
3
KEY INPUT/OUTPUT SCAN CIRCUIT
SEL
KI/O0 KI/O1 KI/O2 KI/O3 KI/O4 KI/O5 KI/O6 KI/O7
FUNCTION DESCRIPTION
(1) Oscillation
The SM5221-001/002 oscillation circuit is designed for use of a 400 kHz or 500 kHz ceramic
resonator, but there may be mutual influence between variations in the IC and ceramic
resonator resulting in abnormal oscillation. The oscillation circuit starts to operate when a key
is depressed.
C
1
C
2
OSCI
OSCO
Page 3
V.2.0 Mar 8,2002
三合微科股½有限公司
S
AM
H
OP
Microelectronics Corp.
SM5221-001/002
32 KEYS ENCODER
(2) Key Scan
A pull-down resistor is inserted
keys are depressed simultaneously, transmission is disabled by the multi-depression
prevention circuit.
When a key is depressed, reading of the custom code and key data code is started, and DOUT
output begins 36 ms later, so that if the key is being depressed during this 36 ms interval one
transmission is performed. If a key is held down for 108 ms or longer, consecutive
transmissions of the leader code only are performed while the key is depressed.
Key Input
Ex. f OSC = 455 kHz
MIN. 36 ms
58.5 to 76.5 ms
108 ms
108 ms
(3) Data Code D
7
Control
Data code D7 can be controlled by this pin, allowing 64 kinds of data to be transmitted.
D7 is set to "0" by connecting the SEL pin to VDD, and to "1" by connecting the SEL pin to
VSS. As the input of this pin is high-impedance, it must be connected to either VDD or VSS.
Page 4
V.2.0 Mar 8,2002
三合微科股½有限公司
S
AM
H
OP
Microelectronics Corp.
SM5221-001/002
32 KEYS ENCODER
TRANSMISSION CODE
(1) DOUT Output
The transmission code consists of a leader code, 16-bit custom code, and 8-bit data code.
The inverse code of the data code is also sent simultaneously, giving a total configuration
of 32 bits per transmission.
C0 C1 C2 C3 C4 C5 C6 C7 C0' C1' C2' C3' C4' C5' C6' C7' D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7
Leader
Code
Custom Code
Custom Code'
Data Code
Data Code
DOUT Output Code
The leader code consists of a 9 ms carrier waveform plus a 4.5 ms OFF waveform, and is
used as the leader for the following code. The code uses the PPM (Pulse Position
Modulation) method, with "1" and "0" differentiated by the time between pulses reference
following diagram. Each code consists of 8 bits, and simultaneous transmission of the
inverse code.
9 ms
4.5 ms
Custom Code'
Custom Code
8 bits
8 bits
18 ms to 36 ms
58.5 to 76.5 ms
Data Code
8 bits
Data Code
8 bits
13.5 ms
Leader
Code
0.56 ms
0.56 ms
2.25 ms
Bit 1
1.125 ms
Bit 0
Page 5
V.2.0 Mar 8,2002
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