# HIGH FREQUENCY DC STEP DOWN, 50% DUTY CYCLE CHOPPER USING IR2153 AND 47N60C3 (MOFET)

#### Dasun Umayanga M. A.

Joined Aug 3, 2019
23

Dear Experts,

This is my circuit diagram,
I am Using
1. SELF-OSCILLATING HALF-BRIDGE DRIVER ( IR2153 )
2. MOSFET ( 47N60C3)

INPUT = 100V DC

REQUIRED OUTPUT up to 100kHz frequency, 50% duty cycle of input which is 50V average output voltage.

I created this circuit diagram and I want to confirm that what I am trying to achieve is possible with my circuit diagram.

Please let me know if I am missing any component or if there are any other improvements.

I am at a deadline for a college project, Please help me with this as soon as possible.

#### Alec_t

Joined Sep 17, 2013
12,444
I suggest you look at a few circuits using that IC to see and understand typical gate drive arrangements. If your load has an inductive component you may need appropriate measures to protect the FET from back-emf damage.

#### Dasun Umayanga M. A.

Joined Aug 3, 2019
23
I suggest you look at a few circuits using that IC to see and understand typical gate drive arrangements. If your load has an inductive component you may need appropriate measures to protect the FET from back-emf damage.
I will take your advice sir, what if I use an anti-parallel diode across the LOAD, will it save my MOSFET

#### Alec_t

Joined Sep 17, 2013
12,444
A suitably-rated reverse-biased diode should protect the FET.

#### Dasun Umayanga M. A.

Joined Aug 3, 2019
23
I have another problem is the circuit sir,

My load is an inductor and I have 30v,5A DC power supply as DC supply

Problem: Power supply is in constant current mode at most of the time and 5A and 8V drop which is the max that I can achieve

Requirement : 12V-15V drop at 1-3Amps

what are the possible ways to achieve this?

#### Alec_t

Joined Sep 17, 2013
12,444
I don't understand why you're using a CC supply or why/where you want a 12V-15V drop. Isn't the aim of your circuit to get 50V (average) from a 100V supply? That's what the thread title indicates.

#### Dasun Umayanga M. A.

Joined Aug 3, 2019
23
I don't understand why you're using a CC supply or why/where you want a 12V-15V drop. Isn't the aim of your circuit to get 50V (average) from a 100V supply? That's what the thread title indicates.
I have achieved the REQUIRED OUTPUT 100kHz frequency, 50% duty cycle of input which is 50V average output voltage with INPUT = 100V DC.

now I am looking for the same circuit with different Load and Input,

My load is inductive load ( more like a primary of the transformer coil ) and I have 30v,5A DC power supply ( UNI-T UTP3315TFL ) as DC supply

Problem: Power supply is in constant current mode (NOT CONSTANT VOLTAGE MODE) at most of the time and 5A and 8V drop which is the max that I can achieve

Requirement: 12V-15V drop ACROSS THE INDUCTOR at 1-3Amps

what are the possible ways to achieve this?

#### Dasun Umayanga M. A.

Joined Aug 3, 2019
23
Circuit Diagram

Components USED

1. MOSFET ( 47N60C3 ) (https://www.infineon.com/dgdl/Infin...n.pdf?fileId=db3a304412b407950112b42dff93492f)
2. Primary Transformer Coil
3.12V. 2A Switching Power Supply
4.function generator ( currently using 66kHz frequency)
5.oscilloscope
6. Schottky Diode ( PMEG100V060ELPD ) (https://assets.nexperia.com/documents/data-sheet/PMEG100V060ELPD.pdf )

oscilloscope output

The required output is mentioned with the circuit diagram.

Questions
1.how to remove the oscillatory part of output?
2. how to get full 12v across the Inductor coil?
3.any other possible ways to achieve the above mentioned required waveform accorss the inductor coil

Extra components Available,
extra 2 of 12v,2A power supply

#### Dasun Umayanga M. A.

Joined Aug 3, 2019
23
I am changing the magnitude of function generator gate signal but that was the best I could achieve

#### Alec_t

Joined Sep 17, 2013
12,444
I think most of the oscillatory noise is due to stray inductance in the gate-driving circuit. Your circuit needs to be very compact with no straggly wires and with minimum stray capacitance. A breadboard is a no-no at high frequencies.