Holtek Semiconductor Inc HT12A, HT12E Datasheet
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
·
V
=5V
DD
HT12A with a 38kHz carrier for infrared
·
transmission medium
Applications
Burglar alarm system
·
Smoke and fire alarm system
·
Garage door controllers
·
Car door controllers
·
General Description
The 212encoders 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
HT12A/HT12E
12
2
Series of Encoders
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
·
via an RF or an infrared transmission medium
upon receipt of a trigger signal. The capability
to select a TE
trigger on the HT12A further enhances the application flexibility of the 2
The HT12A additionally provides a 38kHz carrier for infrared systems.
trigger on the HT12E or a DATA
12
series of encoders.
Selection Table
Function
Part No.
HT12A 8 0 4
HT12E 8 4 0
Note: Address/Data represents pins that can be address or data according to the decoder require
ment.
Address
No.
Address/
Data No.
Data
Oscillator Trigger Package
No.
455kHz
resonator
RC
oscillator
1 April 11, 2000
D8~D11
TE
18 DIP
20 SOP
18 DIP
20 SOP
Carrier
Output
38kHz No
No No
Negative
Polarity
-
Block Diagram
TE trigger
HT12E
HT12A/HT12E
OSC1OSC2
TE
A0
A7
DATA trigger
HT12A
L/M B
A0
A7
O s c illa to r
12 T ra nsm ission
G a te C irc u it
AD8 AD11
X2 X1
O scillator
12 T ra nsm ission
G a te C ir c u it
3 D ivider
¸
12 C ounter &
¸
1 of 12 D ecoder
Binary D etector
576 D ivider
¸
12 C ounter &
¸
1 of 12 D ecoder
Binary D etector
D ata Select
& Buffer
Sync.
Circuit
VDD VSS
D ata Select
& Buffer
Sync.
Circuit
DOUT
DOUT
D8 D11
VDD
VSS
Note: The address data pins are available in various combinations (refer to the address/data table).
2 April 11, 2000
Pin Assignment
HT12A/HT12E
8-A ddress
4-D ata
1
A0
2
A1
3
A2
4
A3
5
A4
6
A5
7
A6
8
A7
9
VSS
HT12A
18 D IP
8-A ddress
4-D ata
NC
18
VDD
17
DOUT
16
X1
15
X2
14
L/M B
13
D11
12
D10
11
D9
10
D8
A0
A1
A2
A3
A4
A5
A6
A7
VSS
20
1
2
3
4
5
6
7
8
9
10
NC
19
VDD
18
DOUT
17
X1
16
X2
15
L/M B
14
D11
13
D10
12
D9
11
D8
HT12A
20 S O P
8-A ddress
4-A ddress/D ata
1
A0
A1
A2
A3
A4
A5
A6
A7
VSS
18
2
17
3
16
4
15
5
14
6
13
7
12
8
11
9
10
H T 1 2 E
1 8 D IP
VDD
DOUT
OSC1
OSC2
TE
AD11
AD10
AD9
AD8
Pin Description
Pin Name I/O
A0~A7 I
AD8~AD11 I
D8~D11 I
DOUT O CMOS OUT Encoder data serial transmission output
L/MB I
Internal
Connection
CMOS IN
Pull-high
(HT12A)
NMOS
TRANSMISSION
GATE
PROTECTION
DIODE
(HT12E)
NMOS
TRANSMISSION
GATE
PROTECTION
DIODE
(HT12E)
CMOS IN
Pull-high
CMOS IN
Pull-high
Description
Input pins for address A0~A7 setting
These pins can be externally set to VSS or left open
Input pins for address/data AD8~AD11 setting
These pins can be externally set to VSS or left open
Input pins for data D8~D11 setting and transmission en
able, active low
These pins should be externally set to VSS or left open
(see Note)
Latch/Momentary transmission format selection pin:
Latch: Floating or VDD
Momentary: VSS
8-A ddress
4-A ddress/D ata
NC
A0
A1
A2
A3
A4
A5
A6
A7
VSS
20
1
19
2
18
3
17
4
16
5
15
6
14
7
13
8
12
9
11
10
H T 1 2 E
2 0 S O P
NC
VDD
DOUT
OSC1
OSC2
TE
AD11
AD10
AD9
AD8
-
3 April 11, 2000
HT12A/HT12E
Pin Name I/O
TE
I
Internal
Connection
CMOS IN
Pull-high
Description
Transmission enable, active low (see Note)
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
VDD I
¾
¾
Negative power supply, grounds
Positive power supply
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
NMOS
TRANSM ISSIO N
GATE
CMOS IN
Pull-high
CMOS OUT OSCILLATOR 1
EN
OSC1
OSC2
OSCILLATOR 2
X1 X2
NMOS TRANSMISSION GATE
PROTECTION DIODE
V
DD
Absolute Maximum Ratings
Supply Voltage (HT12A) ..............-0.3V to 5.5V
Input Voltage....................V
-0.3 to VDD+0.3V
SS
Operating Temperature...............-20°Cto75°C
Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maxi
mum 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 expo
sure to extreme conditions may affect device reliability.
Supply Voltage (HT12E) ...............-0.3V to 13V
Storage Temperature.................-50°Cto125°C
4 April 11, 2000
-
-
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