FM Remote Encoder/Decoder Circuit Working Principle and Applications

Posted on

FM or RF communication is without doubt one of the best wi-fi communication programs to ship the required service. In our earlier article, now we have mentioned Different Types of Wireless Communications. The FM distant encoder and FM decoder circuit present a safe RF communication between two units (transmitter and receiver).

FM Remote Encoder/Decoder Circuit entails two primary elements corresponding to transmitter (encoder) part and receiver (decoder) part. This circuit constructed with an IC RF600E (encoder), IC RF600D (decoder) as its core half.

FM Remote Encoder and Decoder ICs

This FM Remote Encoder and FM Decoder circuit are utilized in many distant management functions. The RF600E and RF600D ICs are designed to attain the utmost potential vary from any radio or infrared transmitter-receiver set. They supply high safety which prevents copying or grabbing whereas additionally acquiring the optimum vary from the transmitter and receiver.

The units are very straightforward to make use of and might be inserted immediately right into a circuit. The units are very straightforward to make use of and might be inserted immediately right into a circuit. The RF600D has a feature enabling as much as 7 distinctive RF600E encoder units in standalone mode or as much as 48 encoder units when it's used along with an external EEPROM.

RF Encoder & FM Decoder IC’s
RF Encoder & FM Decoder IC’s

FM Encoder/ Transmitter Circuit

The FM distant Encoder system makes use of the frequency modulation technique for sign transmission. The transmitter circuit as proven under. IC1 RF600E and its different required elements are related as per the diagram. The pins 1 to 4 is related to 4 switches individually.

FM Remote Encoder Circuit
FM Remote Encoder Circuit

These switches are related to the inputs for IC1. When every enter push button swap is pressed a corresponding code will probably be generated on the pin quantity 6 which is the information output pin.

This encoded sign out there at pin 6 is buffered utilizing the transistor Q1. And additional, it's fed to the enter of a common function FM transmitter module (M1) which is to be transmitted.

FM Encoder IC – RF600E

Pin Description:

RF600E IC out there in 8 pin DIP. The pin description is given under.

Pin Quantity Identify Description
1 S0 Swap enter 0
2 S1 Swap enter 1
3 S2 Swap enter 2
4 S3 Swap enter 3
5 Vss Floor reference Connection
6 OP Information output
7 LED Cathode connection for immediately driving LED throughout transmission
8 Vcc Constructive provide voltage connection


These are the swap inputs. We function them to get up the RF600E and trigger transmission. They switched on to Vcc.

Vcc / Vss

The power provide must be a steady and regulated voltage with <10mV ripple.

Be aware that in idle mode the transmitter present drain is often solely 100nA.


Information Output, this can be a normal CMOS / TTL output that's additional related on to the information enter pin of the RF Module.


A direct LED drive with an internal present restrict of usually 1 mA, operates when the RF600E is in transmitting mode.


  • 2.0-6.6V operation
  • Automated Battery Stage Monitor
  • ‘Manchester’ modulation
  • 8 pin DIP/SOIC package deal

FM Decoder/ Receiver Circuit

FM Decoder/ Receiver Circuit incorporates, the IC2 RF600D and its related elements. Pins 17, 18, 1 and 2 are the digital knowledge output pins of RF600D akin to the enter switches S1 to S4 of the encoder/transmitter circuits.

FM Remote Decoder Circuit- Stand Alone operation
FM Remote Decoder Circuit- Stand Alone operation

The digital knowledge output pins 17,18,1 and 2 are asserted low when the related inputs S1 to S4 on the IC1 RF600E are asserted. Module M2 is a common function FM receiver module which receives the transmitted code by way of an antenna and fed it to the information enter (pin 9) of the IC2.

Swap S6s can be utilized to pick out between latching and momentary digital output perform. In latching mode, digital output pins (OP1 to OP4) are solely asserted for the corresponding transmit sign. In latching mode, the output state is modified to every corresponding transmit sign.

The study swap S5 is used to enter the decoder IC into the “study mode”. Study operation utilizing the push button swap S5 is as follows.

  • Press and launch the push button swap S5.
  • The standing LED D2 will glow when S5 is pressed and will stay ON when S5 is launched.
  • Function the encoder/transmitter as soon as.
  • The standing LED D2 will develop into OFF.
  • Function the encoder/transmitter once more.
  • The standing LED will begin flashing.
  • When the flashing of standing LED stops, the encoder will probably be efficiently taught to the decoder and the transmitter/encoder will now function the receiver/decoder system.

As much as seven encoder/transmitters might be learnt to every RF600D. Pin 3 of IC2 is the transmitter low battery indicator output and pin 11 is the serial knowledge output.

FM Decoder – RF600D

Pin Description:

RF600D IC out there in 18 pin DIP. The pin description is given under.

Pin Quantity

Identify Enter / Output? Description
1 OP3 Out Information Output 3 (S2)
2 OP4 Out Information Output 4 (S3)
3 LB Out Low Battery pin-goes Low when Low Battery Legitimate
4 Vcc In Constructive provide voltage connection
5 Vss In Hook up with GND
6 ECS Out Connects to EEPROM ‘CS’ pin
7 ECLK Out Connects to EEPROM ‘CLK’ pin.

Additionally, units the information mark.

8 EDAT In / Out Connects to EEPROM ‘Information’ pin
9 IN In RF / IR Information enter
10 LRN In Study / Erase Swap Enter & Standing LED Drive
11 SD1 Out Serial Information output
12 LKIN In Choice Hyperlink Enter for Momentary or Latched outputs
13 SLEEP In Excessive = Run, Low = Sleep Mode
14 Vcc In Constructive provide voltage connection
15 Unused N/A No Connection
16 Unused N/A No Connection
17 OP1 Out Information Output 1 (S0)
18 OP2 Out Information Output 2 (S1)


  • 18 pin DIP/SOIC package deal
  • 4 Digital Outputs (15 States)
  • Asynchronous serial interface
  • 4.5V – 5.5V operation

Applications of FM Remote Encoder and Decoder

  • Common Function Remote Management
  • Automotive alarm programs
  • Gate and storage openers
  • Digital door locks
  • Identification tokens
  • Burglar alarm programs

I hope This text given the transient info on FM distant encoder/decoder, RF600E IC and RF600D IC. Moreover, for any queries relating to this text or for any assist in implementing Electrical and Electronics projects, you may contact us or remark within the remark part given under