UC3846: test circuit

Serkan ORHAN

Part Number: UC3846

hello everyone ;

ı wanna design a converter with uc3846.But first tried to make a test circuit to see the output PWM signals.ı made all calculations and drawing .(ı will put them below) but ı can see anything.

ı couldnt understand whats wrong.can someone help me please?

Fswitching=2,2/4,4x0,01=50kHz

dead time =1,62uS

3xIsxRs=(R2xVref/(R1+R2)-0,5)====>Vsmax=IsxRs=1,06V

over 5 years ago

0 Teng Feng over 5 years ago

TI__Genius 13660 points

Hi Serkan, I will get back to you soon.——Teng

0 Teng Feng over 5 years ago in reply to Teng Feng

TI__Genius 13660 points

Hi Serkan,

Sorry for the delay. Your test circuit seems good.

Here is my suggestions.

1. Try to add a RC circuit at CS pin to provide a ramp at CS+ pin.

2. Ensure -E/A pin (Pin6) voltage is smaller than +E/A pin (Pin 5) voltage, and COMP pin (Pin 7) has a voltage larger than 1.5V.

If it still doesn't work, please provide the voltage of VREF pin, EA+ pin, EA- pin and COMP pin and provide the waveform of CT pin and CS+ pin. So that I can help you further.

Regards,

Teng

0 Teng Feng over 5 years ago in reply to Teng Feng

TI__Genius 13660 points

Hi Serkan, I haven’t heard back from you, I’m assuming you were able to resolve your issue. If not, just post a reply below (or create a new thread if the thread has locked due to time-out) – thanks, Teng

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UC3846: test circuit