28-06-2013, 03:18 PM
HT12A/HT12E 212 Series of Encoders
Series of Encoders.pdf (Size: 141.23 KB / Downloads: 12)
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: 0.1A (typ.) at
VDD=5V
HT12A with a 38kHz carrier for infrared
transmission medium
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 12N 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.
Address/data programming (preset)
The status of each address/data pin can be individually pre-set to logic high or low. 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 1A 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