Boost converter using IR2110 and pic microcontroller

Boost converter using IR2110 and pic microcontroller, In this article I am going to post my design of boost converter ? In this article, you will learn what is boost converter? How to design boost converter? How to use MOSFET as a switch in boost converter and how to drive this MOSFET which is connected in low side configuration. Let’s start this article with the basic understanding of boost converter and then I will move forward to circuit diagram of boost converter using 1R2210 MOSFET Gate driver and its functionality.

Preliminary Concepts

Note: In this article, I am just discussing practical aspects to make boost converter . I assume that you know about theoretical calculations of boost converter design and its basic working. If you don’t know about it I recommend you to go through any power electronics book and read chapter on dc to dc converters.

Boost Converter Circuit Diagram

Boost converter is basically a regulator which is used to step up dc voltage without transformer. In other words, it is step up transformer for dc voltage. A basic circuit diagram of boost converter is given below.

circuit diagram of boost dc to dc converter
circuit diagram of boost dc to dc converter

But this circuit diagram is not full circuit diagram according to practical aspects. Because Switch shown in figure below should be replaced with any semiconductor device like transistor, MOSFET and IGBT. Selection of any one of these components as a switch depends on voltage and current rating of any converter. To use these components we also need driver circuits, For example if you are using MOSFET as a switch, then MOSFET may be used as a low side switch or high side switch that’s why you need a driver circuit. In this article, we are using IR2110 MOSFET gate driver IC.

Boost Converter Example

Now I will take one example of boost converter and will show you its circuit diagram which includes all practical aspects which you need to make a boost converter. For example, we want to make a boost converter which input voltage is 12V and output voltage is 20 V at 100Khz frequency. The average load current is .5 A . By using these values and with the help of formula’s of boost converter you can easily calculate values of inductor and capacitor. I am not going to discuss it here. Because there are a lot of basics available on power electronics from where you can read method to calculate values of inductor and capacitor. For example, we calculated following values :

         L = 150uH

         C = 33uF

For boost converter formula to calculate duty cycle or in other word on/off time of MOSFET is given below

out put voltage = input voltage / ( 1 – K ) ;   where K is duty cycle

So by putting values of our example

20 = 12 / 1 – k ;

k = .4 or 40 %

So duty cycle of MOSFET is 40 % to get output voltage of  20 V. To get regulated DC output voltage you should use feedback . For example, if input voltage increases, output voltage will also increase according to above-given formula of duty cycle. But to maintain output votage constant duty cycle should be reduced equal proportion. For this purpose you need to used microcontroller and you should learn how to used microcontroller for PWM generation and to generate PWM with variable duty cycle. If you want to know about  it check following article :

What is pulse width modulation ? 

Pule width modulation using pic microcontller

Circuit diagram of boost converter

Circuit diagram of dc to dc boost converter is given below . Diode D1 should be selected according to average load current. For example in this example average load current is .5 Ampere. So D1 should have at least 1 ampere.  Similarly MOSFET should also be selected according to voltage and current rating of your design requirement.

circuit diagram of boost dc to dc converter using pic microcontroller
circuit diagram of boost dc to dc converter using pic microcontroller

Mosfet is used as a low side configuration . because load is connected to drain of MOSFET. A voltage divider is used to lower voltage to less than 5 volt and then fed to microcontroller ADC pin . Because microcontroller can not read voltage more than 5 volt. This voltage measurement is used to set duty cycle in case of voltage fluctuation at the output. PIC16F877A microcontroller is used to generate PWM.  you should have a knowledge about pic microcontrollers and its programming to write code for PWM and voltage measurement of above circuit diagram.

code of boost converter

After reading this article, you can write your own code, but if you need code you can contact me through email.

15 thoughts on “Boost converter using IR2110 and pic microcontroller”

  1. dear Bilal malik,

    i’m interested to buy the program from you, how much the program and protues too. i need very urgent, need your answer as soon as possible

    regards,
    azlan

    Reply
  2. Dear Bilal Malik,
    I am a EEE student. I chose this project for my final project of Power Electronics lab. But I didn’t realize before starting that the codes were missing. Now my submission date is just 4 days away, and I have already submitted the circuit diagram and cannot change the project topic. Is there any way I can get the codes for this particular project please. I am really stuck and the help will be greatly appreciated.
    Thanks and Best Regards.

    Reply
  3. Why is your diode backwards (cathode is facing the inductor instead of facing the load)? Your load is basically isolated doing that.

    Reply
  4. A couple of little catches:
    1) Diode in this circuit got wrong polarity. It should be cathode to output.
    2) Writing code for boost requires care: do it wrong – and output voltage can go to virtually infinity. Of course you wouldn’t get there – something would blow up before you get there. Like e.g. output capacitor and load.
    3) Boost is inefficient above duty 0.8 to 0.9 – and therefore if you write naive code, you can burn your FET in futile attempt to get desired voltage when load is excessive. Don’t forget duty ratio clamping in your code, pals.

    Reply
      • You’re welcome. I don’t use PICs but I’ve stumbled on comparable (and fairly advanced) buck and boost circuits using AVR and got idea to try same trickery using low-end STM32s I’m fiddling with.

        Just in case, there is also smart modification of buck called “inverted buck” where coil put into negative rail, yet retains its function. This way you could use N-fet and avoid high-side drivers, to extent simplest form of this thing can be directly driven by MCU toggling FET (assuming GPIO can handle desired switching speed of MOSFET in use).

        Some crazy russians used these tricks in software-controlled, very high efficiency high-power flashlights, hitting efficiency over 90% and also doing very clever tricks, like e.g. not just checking LED current and stabilizing that, but also when LiIon cell depletes enough, buck abandons all switching and just completely opens FET – reaching almost 100% efficiency, since current doesn’t exceeds safe LED limit anymore. Ofc it loses current stabilization at this point, led slowly loses brightness when battery voltage gone that low.

        OVP idea also shamelessly “borrowed” from these things.

        If you wonder…
        IRLHS6242 could have “direct drive” by MCU at 100 to 500kHz or so by mere GPIO, boasting shy 12mOhm Rds_on while GPIO can handle its gate charge and have reasonable switching.

        More powerful versions gone for IRLHM620, it fully open by like 2.5-3V, but gate charge is quite high, so GPIO is slow to open. These ppl used TS5A3159 as “GPIO amplifier” – and while it advertised as 1-ohm analog switch, it also makes a decent LOW VOLTAGE low-side driver capable of 2.5..3V operation (LiIon’s lowest voltage).

        Reply
  5. p.s. just in case, you can add fairly easy “hardware” OVP (over-voltage protection). Just connect zener rated slightly above of desired voltage with series resistor to positive side of output, and put NPN BJT so that once zener opens, BJT faces current through it’s base. Ofc it’s emitter should connected to ground, and collector…

    …as you’ve guessed, you should connect PIC and driver IC via some resistor, like maybe 1K in series, and let that BJT to act as crowbar on controlling signal, halting switching if voltage goes really wrong. So if things go out of control, zener opens, current flows through BJT’s base (limited by resistor in series with zener) – BJT opens – and shortcuts driver IC input to ground, halting switching – and therefore prevents damage due to overvoltage. And resistor between microcontroller and driver ensures microcontroller’s output haves limited load defined by this resistor rather than attempts to overpower BJT acting as crowbar. This way such circuit could be much safer to debug and test.

    Reply

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