Working of HT12E Encoder IC

Share on FacebookShare on Google+Tweet about this on TwitterShare on RedditShare on StumbleUponPin on Pinterest
pin-diagram-configuration-IC-HT12E
Pin Diagram of IC HT12E

HT12E is a 2^12 series encoder IC widely used in remote control and very common among Radio Frequency RF applications. This HT12E IC capable of converting 12 bit Parallel data inputs into serial outputs. These bits are classified into 8 (A0-A7) address bits and 4(AD0-AD3) data bits. Using the address pins we can provide 8 bit security code for secured data transmission between the encoder and the decoder. The encoder and decoder should use the same address and data format. HT12E is capable of operating in a wide Voltage range from 2.4V to 12V and also consists of  a built in oscillator. Let’s move into the working of HT12E encoder IC.

PIN DESCRIPTION OF IC HT12E: 

The pin Description of the IC HT12E was pretty simple to understand with total of 18 pins.

  • VDD and VSS: Positive and negative power supply pins.
  • OSC1 and OSC2: Input and output pins of the internal oscillator present inside the IC.
  • TE: This pin is used for enabling the transmission, a low signal in this pin will enable the transmission of data bits.
  • A0 – A7: These are the input address pins used for secured transmission of this data. These pins can be connected to VSS for low signal or left open for high state.
  • AD0 – AD3: This pins are feeding data into the the IC. These pins may be connected to VSS for sending LOW since it is a active low pin
  • DOUT: The output of the encoder can be obtained through  this pin and can be connected to the RF transmitter.

WORKING OF HT12E IC: 

timing-diagram-ht12e-icHT12E starts working with a low signal on the TE pin. After receiving a low signal the HT12E starts the transmission of 4 data bits as shown in the timing diagram above. And the output cycle will repeats based on the status of the TE pin in the IC. If the TE pin retains the low signal the cycle repeats as long as the low signal in the TE pin exists. The encoder IC will be in standby mode if the TE pin is disabled and thus the status of this pin was necessary for encoding process. The address of these bits can be set through A0 – A7 and the same scheme should be used in decoders to  retrieve the signal bits.

PRACTICAL CIRCUIT USING HT12E:

HT12E-practical-application-circuit
Practical Application Circuit

The above diagram shows the practical set up of the HT12E encoder IC for better understanding on the working.

Related Designs and Schematics

Share on FacebookShare on Google+Tweet about this on TwitterShare on RedditShare on StumbleUponPin on Pinterest
The following two tabs change content below.
Frank Donald

Frank Donald

Junior Network Engineer at Tata Communications
Frank Donald is an Electronics and Communication Engineer who loves building stuff in his free time. Video games, blogging and programming are the things he loves most
Frank Donald

Latest posts by Frank Donald (see all)

Ask your query

47 Comments on "Working of HT12E Encoder IC"

Notify of
avatar
Sort by:   newest | oldest | most voted
vatsal
Guest

Hii Frank, I am interfacing 4 encoder with different address configuration.. In ht12d decoder section, i am changing the address by giving delay. But now, if i want to connect more than 4 encoder how do i configure data pins? I know i can give 2^7 different address. But if i want to transmit data in 5th encoder, in which pin of encoder sholud i provide data to encoder???

Sss
Guest

I have a doubt. Why do we put a resistor between two pins of oscillator viz.pin 15 n 16 in ht12e

Gunasekaran
Guest

Dear Frank Donald
I appreciate your clear explanation of the HT12D & E working and using it for RF 433 Mhz transmission. I planning for dynamic addressing the HT12D and HT12E Ics by connecting the ULN 2803 output pins to the address pins of Encoder and Decoder ICs and control the address by Microcontroller. Will this work?

Request you idea on this.

Unk
Guest

So this IC encoding type is kind of OTP encoding, right?

Unk
Guest

Kind of. The differences between both is that the HT12E words, don’t have the 0101 at the end. So there’s no way to filter signals coming from other sources.

Girishkumar
Guest

sir,which algorithm used in this encoder ic ?

Saran
Guest

Sir, i made the address bit as 0 and data as 1000 then the transmitted data is
syn.bit 0 0 0 0 0 0 0 0 1 0 0 0 am i right. Then what about the syn.bit.

Saran
Guest

Sir, which type of encoding technique is used in HT12E?

Kartik Sikka
Guest

What is the frequency of the Serial Data Produced at the OUTPUT pin of the HT12E IC

Santosh G B
Guest

What will be the output of Dout of HT12E if the input signal is from ARM CONTROLLER?

Jatin Goyal
Guest

how many data pins we can give data into ht12e. & why A0-A& pins are used
and i wanna build a 20 channel transmitter so please guide by giving some iinnfo or helpful links

wpDiscuz