3
18
Series of Decoders
Features
•
•
•
•
•
•
•
Operating voltage: 2.4V~12V
Low power and high noise immunity CMOS
technology
Low standby current
Capable of decoding 18 bits of information
Pairs with HOLTEK’s 3
18
series of encoders
8~18 address pins
0~8 data pins
•
•
•
•
•
•
Trinary address setting
Two times of receiving check
Built-in oscillator needs only a 5% resistor
Valid transmission indictor
Easily interface with an RF or an infrared
transmission medium
Minimal external components
Applications
•
•
•
•
Burglar alarm system
Smoke and fire alarm system
Garage door controllers
Car door controllers
•
•
•
•
Car alarm system
Security system
Cordless telephones
Other remote control systems
General Description
The 3
18
decoders are a series of CMOS LSIs for
remote control system applications. They are
paired with the 3
18
series of encoders. For
proper operation a pair of encoder/decoder pair
with the same number of address and data
format should be selected (refer to the en-
coder/decoder cross reference tables).
The 3
18
series of decoders receives serial ad-
dress and data from that series of encoders that
are transmitted by a carrier using an RF or an
IR transmission medium. It then compares the
serial input data twice continuously with its
local address. If no errors or unmatched codes
are encountered, the input data codes are de-
coded and then transferred to the output pins.
The VT pin also goes high to indicate a valid
transmission.
The 3
18
decoders are capable of decoding 18 bits
of information that consists of N bits of address
and 18–N bits of data. To meet various applica-
tions they are arranged to provide a number of
data pins whose range is from 0 to 8 and an
address pin whose range is from 8 to 18. In
addition, the 3
18
decoders provide various com-
binations of address/data number in different
packages.
Selection Table
Function Address
No.
Item
HT602L
HT604L
HT605L
HT611
12
10
9
14
Data
No.
2
4
5
0
VT
L
L
L
Oscillator
Trigger
Package
Type
√
√
√
√
RC oscillator DIN active “Hi” 20 DIP/20 SOP
RC oscillator DIN active “Hi” 20 DIP/20 SOP
RC oscillator DIN active “Hi” 20 DIP/20 SOP
RC oscillator DIN active “Hi” 20 DIP/20 SOP
—
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2nd Oct ’97
3
18
Series of Decoders
Function Address
No.
Item
HT612
HT614
HT615
HT644L
HT646L
HT648L
HT651
HT654
HT656
HT658
HT682L
HT683L
HT684L
HT691
HT692
HT693
HT694
12
10
9
14
12
10
18
14
12
10
10
9
8
12
10
9
8
Data
No.
2
4
5
4
6
8
0
4
6
8
2
3
4
0
2
3
4
VT
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
Oscillator
Trigger
Package
Type
M
M
M
L
L
L
—
M
M
M
L
L
L
—
M
M
M
RC oscillator DIN active “Hi” 20 DIP/20 SOP
RC oscillator DIN active “Hi” 20 DIP/20 SOP
RC oscillator DIN active “Hi” 20 DIP/20 SOP
RC oscillator DIN active “Hi” 24 SOP/24 SDIP
RC oscillator DIN active “Hi” 24 SOP/24 SDIP
RC oscillator DIN active “Hi” 24 SOP/24 SDIP
RC oscillator DIN active “Hi” 24 SOP/24 SDIP
RC oscillator DIN active “Hi” 24 SOP/24 SDIP
RC oscillator DIN active “Hi” 24 SOP/24 SDIP
RC oscillator DIN active “Hi” 24 SOP/24 SDIP
RC oscillator DIN active “Hi” 18 DIP
RC oscillator DIN active “Hi” 18 DIP
RC oscillator DIN active “Hi” 18 DIP
RC oscillator DIN active “Hi” 18 DIP
RC oscillator DIN active “Hi” 18 DIP
RC oscillator DIN active “Hi” 18 DIP
RC oscillator DIN active “Hi” 18 DIP
Note: Data type: M represents momentary type of data output.
L represents latch type of data output.
VT can be used as a momentary data output.
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2nd Oct ’97
3
18
Series of Decoders
Block Diagram
Note: The address/data pins are available in various combinations
(refer to the address/data table).
Pin Description
Pin Name
A0~A17
D10~D17
DIN
VT
OSC1
OSC2
VSS
VDD
I/O
I
O
I
O
I
O
I
I
Internal
Connection
Description
TRANSMISSION Input pins for address A0~A17 setting
GATE
They can be externally set to VDD, VSS, or left open.
CMOS OUT
CMOS IN
CMOS OUT
OSCILLATOR
OSCILLATOR
—
—
Output data pins
Serial data input pin
Valid transmission, active high
Oscillator input pin
Oscillator output pin
Negative power supply (GND)
Positive power supply
3
2nd Oct ’97
3
18
Series of Decoders
Approximate internal connection circuits
Absolute Maximum Ratings*
Supply Voltage ............................... –0.3V to 13V
Input Voltage..................V
SS
–0.3V to V
DD
+0.3V
Storage Temperature................. –50
°
C to 125
°
C
Operating Temperature............... –20
°
C to 75
°
C
*Note: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent
damage to the device. These are stress ratings only. Functional operation of this device at
these or any other conditions above those indicated in the operational sections of this
specification is not implied and exposure to absolute maximum rating conditions for extened
periods may affect device reliability.
Electrical Characteristics
Symbol
V
DD
I
STB
I
DD
(Ta=25
°
C)
Parameter
Operating Voltage
Standby Current
Test Conditions
V
DD
—
5V
12V
Min.
3
—
—
Typ.
—
0.1
2
0.2
–1
1
–4
2
—
—
100
Max.
12
1
4
1
—
—
—
—
5
1
—
Unit
V
Conditions
—
Oscillator stops
No load
F
OSC
=100kHz
V
OH
=4.5V
µ
A
µ
A
mA
mA
mA
mA
mA
V
V
kHz
Operating Current
Data Output Source Current
(D10~D17)
Data Output Sink Current
(D10~D17)
VT Output Source Current
VT Output Sink Current
“H” Input Voltage
“L” Input Voltage
Oscillator Frequency
5V
—
–0.5
0.5
–2
1
3.5
0
—
I
O
5V
V
OL
=0.5V
5V
5V
5V
10V
V
OH
=4.5V
V
OL
=0.5V
—
—
R
OSC
=330k
Ω
I
VT
V
IH
V
IL
F
OSC
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2nd Oct ’97
3
18
Series of Decoders
Functional Description
Operation
Flowchart
The 3
18
series of decoders provides various com-
binations of address and data pins in different
packages. It is paired with the 3
18
series of
encoders. The decoders receive data transmit-
ted by the encoders and interpret the first N
bits of the code period as address and the last
18–N bits as data (where N is the address code
number). A signal on the DIN pin then activates
the oscillator which in turns decodes the incom-
ing address and data. The decoders will check
the received address twice continuously. If all
the received address codes match the contents
of the decoder’s local address, the 18–N bits of
data are decoded to activate the output pins,
and the VT pin is set high to indicate a valid
transmission. That will last until the address
code is incorrect or no signal has been received.
The output of the VT pin is high only when the
transmission is valid. Otherwise it is low al-
ways.
Output type
There are 2 types of output to select from:
•
Momentary type
The data outputs follow the encoder during a
valid transmission and then reset.
•
Latch type
The data outputs follow the encoder during a
valid transmission, and are then latched in
this state until the next valid transmission
occurs.
Note: The oscillator is disabled in the
standby state and activated as long as
a logic “high” signal is applied to the
DIN pin. i.e., the DIN should be kept
“low” if there is no signal input.
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2nd Oct ’97
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