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IC 4047 Datasheet, Pinouts, Application Notes

IC 4047 Datasheet, Pinouts, Application Notes

The IC 4047 is one of those devices which promises an unlimited range of circuit application solutions. The IC is so versatile that on many occasions it easily outsmarts it's close rival, the IC 555, let's study the datasheet and pinout details of this versatile chip.

Main Datasheet and Specifications:

In-built oscillator with variable frequency option through an external RC network.

Complementary push-pull outputs with a separate active clock output, the clock output is actually an extension of the internal oscillator frequency output.

Duty cycle locked to 50% for precision, fail proof operation of the external stages.

The IC 4047 can be configured as a free running astable MV, and also as a monostable MV.

In the astable mode the chip provides the option of integrating external triggering inputs, also called true gating and complement gating modes.

The monostable mode enables positive edge triggering as well as negative edge triggering of the IC.

It further allows retriggerable feature for extending the output timing to the desired calculated level. Meaning after the normal trigger is applied to the IC, more number subsequent triggers can be applied so that the output adds up the timing, generating further delay at the output.

Internal Logic Diagram

IC 4047 internal logic diagram

Pinout Details

The following explanation suggests how the pinouts of the IC 4047 may be configured for implementing the above discussed operating modes:

In the free running astable mode, connect pins 4, 5, 6, 14 to positive or Vdd, connect pins 7, 8, 9, 12 to ground or Vss.

Vdd must be supplied with a recommended 3V to 15V and maximum 18V (absolute).

In gated astable mode connect pins 4, 6, 14 to positive or Vdd, connect pins 7, 8, 9, 12 to ground or Vss, connect pin 5 to the reset pin of the external trigger IC, while output of the external chip to pin 4 of the IC 4047.

For the above modes, the output may be obtained across pin 10, 11 (push-pull) while clocks at pin 13.

In positive trigger monostable mode, connect pins 4, 14 to positive or Vdd, connect pins 5, 6, 7, 9, 12 to ground or Vss, connect pin 8 to the reset pin of the external trigger IC, while output of the external chip to pin 6 of the IC 4047.

For the above modes, the output may be obtained across pin 10, 11.

Fundamental Free Running Astable Mode Circuit Diagram Using IC 4047

IC 4047 pinout hints

As shown in the figure above, the IC 4047 can be used as a free running astable multivibrator or oscillator by configuring the chip in the above suggested method.

Here R1, P1 and C1 determine the oscillator frequency of the IC and the output at pin10, 11 and 13.

Basically R1, P1 togeter must not be less than 10K, and above 1M, while C1 should not be less than 100pF (higher value have no restrictions) in order to maintain proper functioning of the chip.

Pin 10 and 11 are complementary outputs which behave in a  push-pull manner, meaning when pin10 is high pin11 is low and vice versa.

Pin 13 is the clock output of the IC 4047, each high pulse measured at this output enables pin10/11 to change positions with their logic levels, while low logics does not influence any response on pin10/11.

Pin13 is normally kept open when not in use, it may be applied in cases where a frequency or pulsed output may be required for the other stages of the circuit for enhancing purposes, such as for making modified PWM based inverters etc.

Electrical Specifications

IC 4047 electrical specifications

Application Notes:

The IC is best suited for all types of inverter, converter, SMPS and timer applications.

One typical simple square wave inverter application using the IC 4047 can be witnessed below:

The formula for calculating the frequency or the RC components are:

f = 1/8.8RC at pin#10 and pin#11

f = 1/4.4RC at pin#13

Where f is in Hz, R in Ohms and C in Farads.

Pulse time may be obtained by solving:

t = 2.48RC where t is in seconds, R in Ohms and C in Farads


About the Author

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. If you have any circuit related query, you may interact through comments, I'll be most happy to help!

80 thoughts on “IC 4047 Datasheet, Pinouts, Application Notes”

  1. swagatam sir,
    I have to design a inverter 1KW sine wave will you please suggest how to calculate required MOSFET, IC and resistors and capacitors for required frequency and also for protection and charging circuit

    • Hi Vaibhav,
      the mosfet’s Drain-Source Voltage must be ideally twice the battery voltage and Continuous Drain Current should be at least 1.5 times higher than the transformer current rating.

      For the above mentioned designs all resistors will be 1/4 watt 1% rated, and capacitors voltage should be rated twice the battery voltage

        • According to me those are not relevant to the ICs main technical specifications, so far whenever I have purchased ICs I have looked into the main number for example in this case only the 4047 is relevant and important rest of the things can be ignored….unless there is a CMOS version, for example (7)555 is the CMOS version of IC 555 and may have some technical differences.

          • Again thanks for answering, another one are different manufacturers have same dimensions of IC for example I have to replace it on PCB board the dimensions of the hole are same?

            • you are welcome, the dimensions are always standard and precisely identical for all brands that are assigned with same number and package specs.

  2. Respected swagatam,
    I have made small 200w inverter it’s running good but the one filp out 4047 mosfet is to much heating !
    I use 4047 ic for ocillator and mosfet is IRF540 use I doing a tryed to
    1)Chang old to new mosfet
    2)inter changing of mosfet
    3) transformer connection Chang
    4)Chang with mosfet gate connection to each other

    • Hello Kanji, If you have swapped the transformer taps with the two mosfets and still experiencing the same issue then that’s very strange, and that looks impossible.

      either the mosfet which is heating up could be faulty, or that particular side winding of the trafo could have issues….if all these parameters are swapped, and still the new arrangement is showing heating issues, then that’s understandable.

      now the only option left is to swap the 4047 output pinouts, and also the replace the gate resistors of the mosfets, and check the results.

  3. I have checked the output pins through headphones but I didn’t hear any oscillating sound. I think the oscillation is not working. Can you please tell why this is happening? I have tried 10 or 12 ICs and 14 mosfet so all of them couldn’t be damage

    • If the IC is configured correctly then it should work, there are only two parts that needs to be connected with the IC for a proper working of the IC….and also there are a few pins which must correctly joined with the supply rails…you can confirm the connections from the datasheet of the IC or from other online sources also and check whether you have connected all of them correctly.

  4. Hi,

    Above details give osc output as 1/4.4RC(Tosc = 4.4RC) and Q output as 1/8.8RC (TQ = 8.8RC). But the datasheet says Tosc is 2.2RC and TQ is 4.4RC ( 2*(Ton + Toff)). So how you end up in above equation?

    • Hi, the data was referred from another website so I can’t suggest much on that, you can solve in both ways and test piratically to see which one gives you the right results.

  5. However if I set my multimeter in AC and check the output of the ic I get 27v. Instead of 12v or 6v. I also checked AC current in the battery there is also showing 27v. I think oscillation is not working and I am getting input = output

    • which capacitor are you referring to? the pin#1 cap is rightly placed.

      use a non-polar cap, and confirm that the IC is oscillates, using a headphone across the outputs, if the IC does not oscillate then the fets will quickly get damaged

      • join a flexible wire from the bottom of the headphone pin (earth), then connect the end of wire to one of the outputs of the IC, and the tip of the pin with the other output, and vary the preset…it should produce a varying tone

  6. Hello I have tested my circuit again with different MOSFETs and IC, results were same the output from the IC is 12v. When ever I connect the transformer connection between negative and source of MOSFETs gets broken please see the images in the link
    Circuit https://imgur.com/gallery/4bfcj

    • This can never happen if everything’s correct in your circuit, I suspect your mosfets have problems or your mosfet connections

      The way you have soldered looks very messy, you must clean the soldering with acetone or some cleaning agent, mosfets are extremely sensitive devices sand will burn with slightest inaccuracy. better use a PCB.

      initially try with TIP122 instead of mosfets…that will give a clear idea regarding the proceedings, use a 10K base resistor if you are using this BJT

    • with DC meter it should be 50% less than the supply, and using a frequency meter you must be able to read oscillations, which must change in response to varying of the R/C parts.

  7. what is the output waveform voltage(square wave) amplitude of the inverter which is to be appear across the transformer primary?

    • ok sir . when we conncetd the syetsm as it is given in the circuit, the output was 220v (approx) thats okay…but the transformer input (primary) voltage was very less (in milivolts).so how can it step up to 220v as the voltage ratio is 12/220v…..so theoretically i think trns. primary voltage should be 12 v square wave because the output voltage is 220v square square wave ac.Am i right?
      Is there any specific formula to calculate it?

    • Tushar, across which points did you check the voltage? you must check it across the drain of the mosfet and the negative of the battery, or the across the drain/source leads.

      but first you must connect a load at the output to confirm if the inverter was actually working in the way it is expected to work…if the load operates correctly, then you can go ahead with the voyage measurements.

    • sir,actually i was checking voltage across the drain terminals of mosfets as it is directly connected to the transformer primary.and yes we have checked the system with load also.

      thank you so much sir for your answer,now i will check the voltage across drain and negative.

    • Hello Paras, no it is not possible to make a 3 phase inverter using a 4047 IC…..special driver ICs will be required for this…I have posted many related article in this website, you may check them out through the search box

  8. hi so if i adjust the oscillator from cd4047 to be 50hz using the 1/8.8RC formula, i'll be feeding the same freq to the transformer input right? So at the output i'll get 230Vac 50Hz?

    • the frequency at each of the IC pins which are connected with the mosfets gates must be 50Hz…then your output will also be 50Hz

  9. hi sir… can i used this cd4047 for DC CDI for motorcycle which this ic hv trigger pin for input pulse from magnet pulser.tx verry much

  10. sir
    I have made an inverter with ic cd4047
    which has 12v DC input . I want to increase the input voltage 12v to 24v what changes I have to done with the circuit???

    • jose, PWM is not used in the above design.

      if ferrite core is used then the frequency must be set to around 30kHz, for iron core it can be 50 or 60Hz

  11. hello Sir! I want built a 100W solar inverter for project ….how can I increase the efficiency or what are the components that I may use for that purpose…can you suggest me with a circuit diagram

    • hello joydeep, efficiency normally depends on the overall transformer quality and the battery AH level, if you are able to get these two parameters optimally then your inverter would work with maximum efficiency.

  12. Hello sir,
    Can i use this circuit in 300 w inverter by using more MOSFET and using relay for charging the battery .

    • Hello Mayank,

      you can make a 300 watt inverter by using IRF540 or any similar mosfet….more mosfets in parallel may not be required.

    • Hi Mayank,
      an oscillator is a circuit which is able to produce alternate positive and negative voltages at its output at a given specified frequency

    • Sir i have designed inverter (12v dc to 220v ac) using IC4047, it's output is well enough when ever i test in bread board but when i do solding and wireing output voltage drop too much, whats the reason for that?.
      kindly mail me in wasiqullah1@gmail.com
      i will thankfull to you.

    • Wasiq, PCB assembly will normally produce better results than breadboard, so your problem could be due to some hidden fault…..please check and compare each and every connection patiently and carefully, for troubleshooting the issue.

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