HOLTEK HT12A

2
12
HT12A/HT12E
Series of Encoders
Features
·
·
·
·
Operating voltage
- 2.4V~5V for the HT12A
- 2.4V~12V for the HT12E
Low power and high noise immunity CMOS
technology
Low standby current: 0.1mA (typ.) at
VDD=5V
HT12A with a 38kHz carrier for infrared
transmission medium
·
·
·
·
Minimum transmission word
- Four words for the HT12E
- One word for the HT12A
Built-in oscillator needs only 5% resistor
Data code has positive polarity
Minimal external components
HT12A/E: 18-pin DIP/20-pin SOP package
·
·
·
·
Car alarm system
Security system
Cordless telephones
Other remote control systems
·
Applications
·
·
·
·
Burglar alarm system
Smoke and fire alarm system
Garage door controllers
Car door controllers
General Description
The 212 encoders are a series of CMOS LSIs for
remote control system applications. They are
capable of encoding information which consists
of N address bits and 12-N data bits. Each address/data input can be set to one of the two
logic states. The programmed addresses/data
are transmitted together with the header bits
via an RF or an infrared transmission medium
upon receipt of a trigger signal. The capability
to select a TE trigger on the HT12E or a DATA
trigger on the HT12A further enhances the application flexibility of the 212 series of encoders.
The HT12A additionally provides a 38kHz carrier for infrared systems.
Selection Table
Function Address Address/ Data
Oscillator
No.
Data No. No.
Part No.
Trigger
Package
Carrier
Output
Negative
Polarity
HT12A
8
0
4
455kHz
resonator
D8~D11
18 DIP
20 SOP
38kHz
No
HT12E
8
4
0
RC
oscillator
TE
18 DIP
20 SOP
No
No
Note: Address/Data represents pins that can be address or data according to the decoder requirement.
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April 11, 2000
HT12A/HT12E
Block Diagram
TE trigger
HT12E
O S C 2
O S C 1
O s c illa to r
T E
A 0
1 2 T r a n s m is s io n
G a te C ir c u it
A 7
D a ta S e le c t
& B u ffe r
¸ 3 D iv id e r
D O U T
S y n c .
C ir c u it
¸ 1 2 C o u n te r &
1 o f 1 2 D e c o d e r
B in a r y D e te c to r
A D 8
A D 1 1
V D D
V S S
DATA trigger
HT12A
X 2
X 1
O s c illa to r
D a ta S e le c t
& B u ffe r
¸ 5 7 6 D iv id e r
L /M B
A 0
1 2 T r a n s m is s io n
G a te C ir c u it
A 7
D O U T
S y n c .
C ir c u it
¸ 1 2 C o u n te r &
1 o f 1 2 D e c o d e r
B in a r y D e te c to r
D 8
D 1 1
V D D
V S S
Note: The address data pins are available in various combinations (refer to the address/data table).
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April 11, 2000
HT12A/HT12E
Pin Assignment
8 -A d d re s s
4 -D a ta
8 -A d d re s s
4 -D a ta
8 -A d d re s s
4 -A d d r e s s /D a ta
8 -A d d re s s
4 -A d d r e s s /D a ta
N C
1
2 0
N C
N C
1
2 0
N C
A 0
1
1 8
V D D
A 0
2
1 9
V D D
A 0
1
1 8
V D D
A 0
2
1 9
V D D
A 1
2
1 7
D O U T
A 1
3
1 8
D O U T
A 1
2
1 7
D O U T
A 1
3
1 8
D O U T
A 2
3
1 6
X 1
A 2
4
1 7
X 1
A 2
3
1 6
O S C 1
A 2
4
1 7
O S C 1
A 3
4
1 5
X 2
A 3
5
1 6
X 2
A 3
4
1 5
O S C 2
A 3
5
1 6
O S C 2
A 4
5
1 4
L /M B
A 4
6
1 5
L /M B
A 4
5
1 4
T E
A 4
6
1 5
T E
A 5
6
1 3
D 1 1
A 5
7
1 4
D 1 1
A 5
6
1 3
A D 1 1
A 5
7
1 4
A D 1 1
A 6
7
1 2
D 1 0
A 6
8
1 3
D 1 0
A 6
7
1 2
A D 1 0
A 6
8
1 3
A D 1 0
A 7
8
1 1
D 9
A 7
9
1 2
D 9
A 7
8
1 1
A D 9
A 7
9
1 2
A D 9
V S S
9
1 0
D 8
V S S
1 0
1 1
D 8
V S S
9
1 0
A D 8
V S S
1 0
1 1
A D 8
H T 1 2 A
2 0 S O P
H T 1 2 A
1 8 D IP
H T 1 2 E
1 8 D IP
H T 1 2 E
2 0 S O P
Pin Description
Pin Name
I/O
Internal
Connection
Description
CMOS IN
Pull-high
(HT12A)
A0~A7
AD8~AD11
I
I
NMOS
Input pins for address A0~A7 setting
TRANSMISSION These pins can be externally set to VSS or left open
GATE
PROTECTION
DIODE
(HT12E)
NMOS
TRANSMISSION
Input pins for address/data AD8~AD11 setting
GATE
PROTECTION These pins can be externally set to VSS or left open
DIODE
(HT12E)
D8~D11
I
CMOS IN
Pull-high
DOUT
O
CMOS OUT
L/MB
I
CMOS IN
Pull-high
Input pins for data D8~D11 setting and transmission enable, active low
These pins should be externally set to VSS or left open
(see Note)
Encoder data serial transmission output
Latch/Momentary transmission format selection pin:
Latch: Floating or VDD
Momentary: VSS
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April 11, 2000
HT12A/HT12E
I/O
Internal
Connection
TE
I
CMOS IN
Pull-high
OSC1
I
OSCILLATOR 1
Oscillator input pin
OSC2
O
OSCILLATOR 1
Oscillator output pin
X1
I
OSCILLATOR 2
455kHz resonator oscillator input
X2
O
OSCILLATOR 2
455kHz resonator oscillator output
VSS
I
¾
Negative power supply, grounds
VDD
I
¾
Positive power supply
Pin Name
Description
Transmission enable, active low (see Note)
Note: D8~D11 are all data input and transmission enable pins of the HT12A.
TE is a transmission enable pin of the HT12E.
Approximate internal connections
N M O S
T R A N S M IS S IO N
G A T E
C M O S IN
P u ll- h ig h
C M O S O U T
O S C IL L A T O R 1
E N
O S C 1
O S C IL L A T O R
X 1
O S C 2
N M O S T R A N S M IS S IO N G A T E
P R O T E C T IO N D IO D E
2
X 2
V
D D
Absolute Maximum Ratings
Supply Voltage (HT12A) ..............-0.3V to 5.5V
Supply Voltage (HT12E) ...............-0.3V to 13V
Input Voltage....................VSS-0.3 to VDD+0.3V
Storage Temperature.................-50°C to 125°C
Operating Temperature...............-20°C to 75°C
Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maximum Ratings² may cause substantial damage to the device. Functional operation of this device
at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.
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April 11, 2000
HT12A/HT12E
Electrical Characteristics
Ta=25°C
HT12A
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
2.4
3
5
V
¾
0.1
1
mA
¾
0.1
1
mA
No load
fOSC=455kHz
¾
200
400
mA
¾
400
800
mA
VOH=0.9VDD (Source)
-1
-1.6
¾
mA
VOL=0.1VDD (Sink)
2
3.2
¾
mA
VDD
Conditions
¾
¾
VDD
Operating Voltage
ISTB
Standby Current
IDD
Operating Current
IDOUT
Output Drive Current
5V
VIH
²H² Input Voltage
¾
¾
0.8VDD
¾
VDD
V
VIL
²L² Input Voltage
¾
¾
0
¾
0.2VDD
V
RDATA
D8~D11 Pull-high
Resistance
5V
¾
150
300
kW
3V
5V
3V
5V
Oscillator stops
VDATA=0V
Ta=25°C
HT12E
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
2.4
5
12
V
¾
0.1
1
mA
¾
2
4
mA
¾
40
80
mA
¾
150
300
mA
VOH=0.9VDD (Source)
-1
-1.6
¾
mA
VOL=0.1VDD (Sink)
1
1.6
¾
mA
VDD
Conditions
¾
¾
VDD
Operating Voltage
ISTB
Standby Current
IDD
Operating Current
No load
12V fOSC=3kHz
IDOUT
Output Drive Current
5V
VIH
²H² Input Voltage
¾
¾
0.8VDD
¾
VDD
V
VIL
²L² Input Voltage
¾
¾
0
¾
0.2VDD
V
fOSC
Oscillator Frequency
5V
ROSC=1.1MW
¾
3
¾
kHz
RTE
TE Pull-high Resistance
5V
VTE=0V
¾
1.5
3
MW
3V
12V
Oscillator stops
3V
5
April 11, 2000
HT12A/HT12E
Functional Description
Operation
The 212 series of encoders begin a 4-word transmission cycle upon receipt of a transmission enable
(TE for the HT12E or D8~D11 for the HT12A, active low). This cycle will repeat itself as long as the
transmission enable (TE or D8~D11) is held low. Once the transmission enable returns high the encoder output completes its final cycle and then stops as shown below.
T E
< 1 w o rd
E n c o d e r
D O U T
T r a n s m itte d
C o n tin u o u s ly
4 w o rd s
4 w o rd s
Transmission timing for the HT12E
D 8 ~ D 1 1
K e y - in
< 1 w o rd
E n c o d e r
D O U T
w ith 3 8 k H z c a r r ie r
T r a n s m itte d
C o n tin u o u s ly
1 w o rd
1 w o rd
Transmission timing for the HT12A (L/MB=Floating or VDD)
D 8 ~ D 1 1
K e y - in
( a ll d a ta = 1 )
7 w o rd s
< 1 w o rd
E n c o d e r
D O U T
T r a n s m itte d
C o n tin u o u s ly
7 w o rd s
1 w o rd
( a ll d a ta = 1 )
1 w o rd
Transmission timing for the HT12A (L/MB=VSS)
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April 11, 2000
HT12A/HT12E
Information word
If L/MB=1 the device is in the latch mode (for use with the latch type of data decoders). When the transmission enable is removed during a transmission, the DOUT pin outputs a complete word and then
stops. On the other hand, if L/MB=0 the device is in the momentary mode (for use with the momentary
type of data decoders). When the transmission enable is removed during a transmission, the DOUT
outputs a complete word and then adds 7 words all with the ²1² data code.
An information word consists of 4 periods as illustrated below.
1 /3 b it s y n c . p e r io d
a d d r e s s c o d e p e r io d
p ilo t p e r io d ( 1 2 b its )
d a ta c o d e
p e r io d
Composition of information
Address/data waveform
Each programmable address/data pin can be externally set to one of the following two logic states as
shown below.
fO
S C
"O n e "
"Z e ro "
A d d re s s /
D a ta B it
Address/Data bit waveform for the HT12E
fO
S C
3 8 k H z
c a r r ie r
"O n e "
D a ta B it
"Z e ro "
D a ta B it
"O n e "
A d d r e s s B it
"Z e ro "
A d d r e s s B it
Address/Data bit waveform for the HT12A
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April 11, 2000
HT12A/HT12E
The address/data bits of the HT12A are transmitted with a 38kHz carrier for infrared remote controller flexibility.
Address/data programming (preset)
The status of each address/data pin can be individually pre-set to logic ²high² or ²low². If a transmission-enable signal is applied, the encoder scans and transmits the status of the 12 bits of address/data serially in the order A0 to AD11 for the HT12E encoder and A0 to D11 for the HT12A
encoder.
During information transmission these bits are transmitted with a preceding synchronization bit. If
the trigger signal is not applied, the chip enters the standby mode and consumes a reduced current of
less than 1mA for a supply voltage of 5V.
Usual applications preset the address pins with individual security codes using DIP switches or PCB
wiring, while the data is selected by push buttons or electronic switches.
The following figure shows an application using the HT12E:
O S C 1
O S C 2
T r a n s m is s io n
m e d iu m
D O U T
V D D
V
A 0
A 1
A 2
A 3
A 4
A 5
A 6
A 7
V S S
T E
A D 8
A D 9 A D 1 0 A D 1 1
D D
V S S
The transmitted information is as shown:
Pilot
&
Sync.
A0
A1
A2
A3
A4
A5
A6
A7
AD8
AD9
1
0
1
0
0
0
1
1
1
1
8
AD10 AD11
1
0
April 11, 2000
HT12A/HT12E
Address/Data sequence
The following provides the address/data sequence table for various models of the 212 series of
encoders. The correct device should be selected according to the individual address and data requirements.
Part No.
Address/Data Bits
0
1
2
3
4
5
6
7
8
9
10
11
HT12A
A0
A1
A2
A3
A4
A5
A6
A7
D8
D9
D10
D11
HT12E
A0
A1
A2
A3
A4
A5
A6
A7
AD8
AD9 AD10 AD11
Transmission enable
For the HT12E encoders, transmission is enabled by applying a low signal to the TE pin. For the
HT12A encoders, transmission is enabled by applying a low signal to one of the data pins D8~D11.
Two erroneous HT12E application circuits
The HT12E must follow closely the application circuits provided by Holtek (see the ²Application circuits²).
· Error: AD8~AD11 pins input voltage > VDD+0.3V
O S C 2
V D D
O S C 1
A D 1 1
T E
A D 1 0
A D 9
V S S
A D 8
1 2 V
H T 1 2 E
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April 11, 2000
HT12A/HT12E
· Error: The IC¢s power source is activated by pins AD8~AD11
1 2 V
O S C 2
V D D
O S C 1
A D 1 1
T E
A D 1 0
A D 9
V S S
A D 8
H T 1 2 E
Flowchart
· HT12A
· HT12E
N o
P o w e r o n
P o w e r o n
S ta n d b y m o d e
S ta n d b y m o d e
N o
D a ta e n a b le ?
Y e s
T r a n s m is s io n
e n a b le d ?
Y e s
4 d a ta w o rd s
tr a n s m itte d
D a ta w ith c a r r ie r
s e r ia l o u tp u t
D a ta s till e n a b le d ?
Y e s
N o
N o
L /M B = G N D ?
T r a n s m is s io n
s till e n a b le d
Y e s
4 d a ta w o rd s
tr a n s m itte d
c o n tin u o u s ly
Y e s
N o
S e n d th e
la s t c o d e
S e n d ² 1 ² 7 tim e s fo r
a ll o f th e d a ta c o d e s
Note: D8~D11 are transmission enables of the HT12A.
TE is the transmission enable of the HT12E.
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April 11, 2000
HT12A/HT12E
Oscillator frequency vs supply voltage
fO S C
(S c a le )
R
(W )
O S C
7 .0 0
4 7 0 k
5 1 0 k
6 .0 0
5 6 0 k
6 2 0 k
5 .0 0
6 8 0 k
7 5 0 k
4 .0 0
8 2 0 k
9 1 0 k
1 .0 M
(3 k H z )3 .0 0
1 .2 M
1 .5 M
2 .0 0
2 .0 M
1 .0 0
2
3
4
5
6
7
8
9
1 0
1 1
1 2
1 3
V
D D
(V D C )
The recommended oscillator frequency is fOSCD (decoder) @ 50 fOSCE (HT12E encoder)
1
@ fOSCE (HT12A encoder)
3
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April 11, 2000
HT12A/HT12E
Application Circuits
V
1
2
3
4
5
6
7
8
9
A 0
V D D
A 1
D O U T
A 2
X 1
A 3
X 2
A 4
L /M B
A 5
D 1 1
A 6
D 1 0
A 7
D 9
V S S
D 8
1 0 0 W
D D
T r a n s m itte r C ir c u it
V
1 8
1
A 0
V D D
1 8
2
A 1
D O U T
1 7
3
A 2
O S C 1
1 6
4
A 3
O S C 2
1 5
1 4
5
A 4
T E
1 4
1 3
6
A 5
A D 1 1
1 3
1 2
7
A 6
A D 1 0
1 2
1 1
8
A 7
A D 9
1 1
1 0
9
V S S
A D 8
1 7
1 0 k W
1 6
4 5 5 k W
1 5
8 0 5 0
1 0 0 p F
1 0 M W
1 0 0 p F
H T 1 2 A
R
D D
O S C
1 0
H T 1 2 E
Note: Typical infrared diode: EL-1L2 (KODENSHI CORP.)
Typical RF transmitter: JR-220 (JUWA CORP.)
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April 11, 2000
HT12A/HT12E
Holtek Semiconductor Inc. (Headquarters)
No.3 Creation Rd. II, Science-based Industrial Park, Hsinchu, Taiwan, R.O.C.
Tel: 886-3-563-1999
Fax: 886-3-563-1189
Holtek Semiconductor Inc. (Taipei Office)
5F, No.576, Sec.7 Chung Hsiao E. Rd., Taipei, Taiwan, R.O.C.
Tel: 886-2-2782-9635
Fax: 886-2-2782-9636
Fax: 886-2-2782-7128 (International sales hotline)
Holtek Semiconductor (Hong Kong) Ltd.
RM.711, Tower 2, Cheung Sha Wan Plaza, 833 Cheung Sha Wan Rd., Kowloon, Hong Kong
Tel: 852-2-745-8288
Fax: 852-2-742-8657
Copyright Ó 2000 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek
assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are
used solely for the purpose of illustration and Holtek makes no warranty or representation that such applications
will be suitable without further modification, nor recommends the use of its products for application that may present a risk to human life due to malfunction or otherwise. Holtek reserves the right to alter its products without prior
notification. For the most up-to-date information, please visit our web site at http://www.holtek.com.tw.
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April 11, 2000