Now let us check this calculator for the SG3525 IC. Here this calculator will estimate the oscillator frequency based on the timing components as given below:
- Rt = timing resistor (Ohms)
- Ct = timing capacitor (Farads or µF)
- Dead Time (optional)
Calculator by homemade-circuits.com
SG3525 Frequency Calculator
SG3525 Oscillator Frequency Formula:
f = 1 / ( (0.7 * Rt + 3 * Rd) * Ct )If you are not using a dead-time resistor (Rd) then simplified formula is:
f = 1 / ( 0.7 * Rt * Ct )In the above calculator the user can:
- Enter
Rtin kΩ - Enter
Ctin nF - (Optional) Enter
Rdin kΩ if needed
Example:
| Rt | Ct | Rd | Frequency |
|---|---|---|---|
| 10 kΩ | 1 nF | (none) | ≈ 142.85 kHz |
| 10 kΩ | 10 nF | (none) | ≈ 14.28 kHz |
| 10 kΩ | 1 nF | 2.2 kΩ | ≈ 92.17 kHz |
SG3525 Duty Cycle Calculator
SG3525 Duty Cycle Calculator
PWM Pulse Width Calculator
SG3525 PWM Pulse Width Calculator
Transformer Turns Calculator (For Full Bridge or Push-Pull)
Assuming the turns and voltage ratio formula is:
Vp / Vs = Np / Ns
can you kindly show me a half bridge topology SMPS diagram with parts ID?
I almost finished my diy SMPS project but I can’t even to oscillate it.
it has a good square wave 30khz out on both GDT secondary coil but, when I connect it to the mosfets the SG3525A becomes hot and the gate source 60khz frequency changed. I don’t know what to do next.
I will surely try to solve the problem you are facing. Can you please tell me the exact specifications of your SMPS? Let me know I will try to figure it out.
how thanks for the advise .
the resistor of 100 from pin 7 to groung is it suposed to beconected like that or it is a mistake i thought it is to pin 6
the 100 Ω resistor shown from Pin 7 to ground is a mistake, it should be between Pin 7 to Pin 5 through a resistor, which decides the deadtime
hi, good morning. please how can I get a perfect ferrite core transformer winding for 30KHz, 12v inverter. I have been finding it difficult to do so
Good morning, you can try one of these articles to configure it:
https://www.homemade-circuits.com/?s=smps+calculator
the frequency calculated for Sg3525, 100HZ for instance, is it for the two sides or one side of the oscillator alone?
It is for one side….which should be 50Hz/60Hz, not 100Hz.
hi I have SG3525 like to use I’n ignition coil circuit diagram I need to get CT&CR number
Hi, sorry, i did not understand what you meant by CT and CR numbers?