HT12D Datasheet, PDF (1/9 Pages) Holtek Semiconductor Inc – 2 12 Series of Decoders

2¹² Series of Decoders
Features
· Operating voltage: 2.4V~12V
· Low power and high noise immunity CMOS
technology
· Low standby current
· Capable of decoding 12 bits of information
· Pair with Holtek¢s 2¹² series of encoders
· Binary address setting
· Received codes are checked 3 times
Applications
· Burglar alarm system
· Smoke and fire alarm system
· Garage door controllers
· Car door controllers
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 (re-
fer to the encoder/decoder cross reference ta-
ble). For proper operation, a pair of
encoder/decoder with the same number of ad-
dresses and data format should be chosen.
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 se-
rial input data three times continuously with
· Address/Data number combination
- _{HT12D: 8 address bits and 4 data bits}
- _{HT12F: 12 address bits only}
· Built-in oscillator needs only 5% resistor
· Valid transmission indicator
· Easy interface with an RF or an infrared
transmission medium
· Minimal external components
· Car alarm system
· Security system
· Cordless telephones
· Other remote control systems
their local addresses. If no error or unmatched
codes are found, 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 2¹² series of decoders are capable of decod-
ing informations that consist of N bits of ad-
dress and 12-N bits of data. Of this series, the
HT12D is arranged to provide 8 address bits
and 4 data bits, and HT12F is used to decode 12
bits of address information.
Selection Table
Function _Address
Part No.
No.
HT12D
8
HT12F
12
Data
No. Type
4
L
0
¾
VT Oscillator
Trigger
Package
Ö RC oscillator DIN active ²Hi² 18 DIP/20 SOP
Ö RC oscillator DIN active ²Hi² 18 DIP/20 SOP
Notes: Data type: L stands for latch type data output.
VT can be used as a momentary data output.
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July 12, 1999