ANALOGICTECH SM5021B

三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
GENERAL DESCRIPTION
FEATURES
The SM5021A/B is a h i g h p e r f o r m a n c e
infrared remote control encoder utilizing
CMOS technology. Mode A is a signal-key
control and mode B is a multi-key control
during data transmission, supports eight data
key inputs and a LED output to indicate the
status during transmission.
* Wide operation voltage range, 2.4V to 6V
* Eight data key control
* Option of signal-key or multi-key control
* Two custom codes to separate products
* Auto power off for saving power
* LED output to indicate transmission status
* Direct infrared LED 38KHz modulation output
* Low power consumption
* Paired with SM5032 decoder
* 16 pin DIP or SO package
Auto power off function when key is not
pressed to save power, custom codes to
distinguish different products. SM5021
encoder is paired with SM5032 decoder for
more data control applications.
APPLICATIONS
PIN ASSIGNMENT (TOP VIEW)
* SM3015 Fan Remote Control
* Audio Remote Control
* Toy Remote Control
* Consumer Products Remote Control
C1
C2
K1
K2
K3
K4
K5
Vss
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VDD
DOUT
LEDO
OSC2
OSC1
K8
K7
K6
SM5021A/B
Page 1
V.2.0 Mar 8,2002
三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
BLOCK DIAGRAM
VDD
Vss
OSC1
XTAL OSC
Timing Generator
OSC2
Latch Key
K1
K2
Bit_ CK
Filed_CK
Frame_CK
K3
K4
K5
C1
Encoder
Key In Latcg And
Error Detect
C2
K6
K7
DOUT
Output Drive
K8
LEDO
PIN DESCRIPTION
Pin Name
I/O
Function
C1,C2
I
Custom Code
K1 ~ K8
I
Remote Control Key Inputs
(Built-In Pull-Low Resistor)
Vss
POWER
OSC1
I
455KHz XTAL OSC Pin
OSC2
O
455KHz XTAL OSC Pin
DOUT
O
Signal Output
LEDO
O
Transmission Indicator
VDD
POWER
Positive Power Supply
Negative Power Supply ( Substrate )
Page 2
V.2.0 Mar 8,2002
三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
FUNCTION DESCRIPTION
A. Encoder Singal Output Format
Bit Format
SYSCK / 192
Logic 1 is
Logic 0 is
EMPTY
Frame Format
There are four frames, encoder generates during sending. Each frame contains four field:
a) Frame head / Three-bits
1 1 0 ( Metal option )
b) Custom code / Two-bits
C1
C2
c) Control word / Seven-bits
0000001~1000110
d) Synch field / Four-bits of empty
B. Transmission Code Table
Start Word
Custom Code B1
B2
B3
B4
B5
B6
B7
Transmit
1
1
0
C1
C2
0
0
0
0
0
0
1
K1
1
1
0
C1
C2
0
0
0
0
0
1
0
K2
1
1
0
C1
C2
0
0
0
0
1
0
0
K3
1
1
0
C1
C2
0
0
0
1
0
0
0
K4
1
1
0
C1
C2
0
0
1
0
0
0
0
K5
1
1
0
C1
C2
0
1
0
0
0
0
0
K6
1
1
0
C1
C2
1
0
0
0
0
1
1
K7
1
1
0
C1
C2
1
0
0
0
1
1
0
K8
Page 3
V.2.0 Mar 8,2002
三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
C. Transmission Timing
Key In
t1
OSC
LED
t2
DOUT
Frame 1
t3
Frame 2
Frame 3
Frame 4
t4
* t1: Key pressing > 32ms
* t2: Transmission time t3 + 108ms ( Four frame )
If t1 is over t3 + 108ms, DOUT will be transmitted again.
[ ( Pressing time ) MOD ( t3 + 108ms ) + 1 ] * 108ms + t3
* t3: Oscillator stable time.
OSC * 384 = 0.8ms
* t4: 3-Bits( Head ) + 2-Bits( Custom Code ) + 7-Bits( Data ) + 6-Bits( Empty ) = 18-Bits (27ms)
* OSC: 455KHz resonator
Page 4
V.2.0 Mar 8,2002
三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
D. SM5021A Transmission Waveform
Normal Condition
Key 1
Key2
OSC
LED
DOUT
F1
F2
F3
F4
F1
F2
F3
F4
F1
F2
F3
F4
Overlap Condition
If more than one key is pressed, transmission stops.
Key 1
Key2
t > 32ms
OSC
LED
DOUT
F1
F2
F1
F2
Page 5
F3
F4
V.2.0 Mar 8,2002
三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
E. SM5021B Transmission Waveform
Normal Condition
Key 1
Key2
OSC
LED
DOUT
F1
F2
F3
F1
F4
F2
F3
F4
F1
F2
F3
F4
Overlap Condition
If more than one key is pressed, multi-key data transmission.
Key 1
t > 32ms
Key2
t > t3 + 108ms
OSC
LED
DOUT
K1
K1
F
F
[ K1+K2 ]
F
F
K2
K2
K2
K2
K2
K2
F
F
F
F
F
F
Page 6
V.2.0 Mar 8,2002
三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
ABSOLUTE MAXIMUM RATINGS
Parameter
Symbol Test Conditions
Ratings
Unit
VDD-Vss
-0.3 ~ 6
V
Input Voltage
VI
Vss -0.3 ~ VDD +0.3
V
Output Voltage
VO
Vss -0.3 ~ VDD +0.3
V
Maximum Power Consumption
Pa
500
mW
Supply Voltage
VDD - Vss = 5V
Operating Temperature
Topr
-10 ~ 70
℃
Storage Temperature
Tstg
-40 ~ 125
℃
DC ELECTRICAL CHARACTERISTICS
Parameter
Symbol
Conditions
Limit
Min. Typ. Max.
2.4
Supply Voltage
VDD
Stand-by Current
ISB
Input High Level
VIH
1.5
3.5
V
Input Low Level
VIL
0
1.5
V
DOUT Source Current
IOH
VOH = +2.4V
5
mA
LEDO Source Current
IOH
VOH = +2.4V
7.5
mA
DOUT Sink Current
IOL
VOL = +0.4V
5
mA
VDD - Vss = 3V
OSC stop
all output pins open
Page 7
3
6
Unit
V
μA
1
V.2.0 Mar 8,2002
三合微科股份有限公司
SM5021
SAMHOP Microelectronics Corp.
ENCODER
APPLICATION CIRCUIT
R2
4.7Ω
D2
IR
LED
BT
3V
C1
10u
JP1
JP2
C1
VDD
C2
DOUT
K1
LEDO
K2
OSC2
K3
OSC1
K4
K8
K5
K7
Vss
K6
Q1
NPN
D1
LED
455K
Q2
NPN
R1
1KΩ
SM5021
Page 8
V.2.0 Mar 8,2002