HT12D/HT12F
212 Series of Decoders
Features
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Operating voltage: 2.4V~12V
Built-in oscillator needs only 5% resistor
Valid transmission indicator
Low power and high noise immunity CMOS
technology
Easy interface with an RF or an infrared transmission
medium
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Low standby current
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Capable of decoding 12 bits of information
Binary address setting
Minimal external components
Pair with Holtek¢s 212 series of encoders
18-pin DIP, 20-pin SOP package
Received codes are checked 3 times
Address/Data number combination
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HT12D: 8 address bits and 4 data bits
HT12F: 12 address bits only
Applications
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Burglar alarm system
Car alarm system
Smoke and fire alarm system
Garage door controllers
Car door controllers
Security system
Cordless telephones
Other remote control systems
General Description
The 212 decoders are a series of CMOS LSIs for remote
control system applications. They are paired with
Holtek¢s 212 series of encoders (refer to the encoder/de-
coder cross reference table). For proper operation, a
pair of encoder/decoder with the same number of ad-
dresses and data format should be chosen.
ously with their local addresses. If no error or un-
matched codes are found, the input data codes are
decoded and then transferred to the output pins. The VT
pin also goes high to indicate a valid transmission.
The 212 series of decoders are capable of decoding
informations that consist of N bits of address and 12-N
bits of data. Of this series, the HT12D is arranged to pro-
vide 8 address bits and 4 data bits, and HT12F is used to
decode 12 bits of address information.
The decoders receive serial addresses and data from a
programmed 212 series of encoders that are transmitted
by a carrier using an RF or an IR transmission medium.
They compare the serial input data three times continu-
Selection Table
Function
Data
Type
Address
No.
VT
Oscillator
Trigger
Package
No.
4
Part No.
HT12D
HT12F
8
L
RC oscillator
RC oscillator
18DIP, 20SOP
18DIP, 20SOP
Ö
Ö
DIN active ²Hi²
DIN active ²Hi²
12
0
¾
Notes: Data type: L stands for latch type data output.
VT can be used as a momentary data output.
Rev. 1.10
1
November 18, 2002