cupoftea
Advanced Member level 6
Hi,
I have just calculated the current feedback loop for the LT1248 Average current mode PFC controller, for a 150W PFC.
I followed the equations on page 7 to 8 of the LT1509 datasheet. When I conform to their equations, the mains input waveform is a very poor sinusoid. Then, when I just tweak the current error amp compensation components, then I can get a great sinusoidal mains input current…however, the values I use for that are values that fail the requirements of the LT1509 datasheet calculations
Can you say whats going on with the current error amplifier compensation equations on page 7 and 8 of of he LT1509 datasheet? Why do they give compensation R and C values , which basically, do not work?
LT1509
LT1248
...by the way, when i say the waveform is wrong, i mean the waveform i see on the LTspice simulator.
Also, how much does it cost to hire a Ridley Gain phase analyser?...i can see buy price, but not hire price on the web. With the AP gain phase analyser, we can measure the feedback loop gain and phase margins of the PFC.
I have just calculated the current feedback loop for the LT1248 Average current mode PFC controller, for a 150W PFC.
I followed the equations on page 7 to 8 of the LT1509 datasheet. When I conform to their equations, the mains input waveform is a very poor sinusoid. Then, when I just tweak the current error amp compensation components, then I can get a great sinusoidal mains input current…however, the values I use for that are values that fail the requirements of the LT1509 datasheet calculations
Can you say whats going on with the current error amplifier compensation equations on page 7 and 8 of of he LT1509 datasheet? Why do they give compensation R and C values , which basically, do not work?
LT1509
LT1248
--- Updated ---
...by the way, when i say the waveform is wrong, i mean the waveform i see on the LTspice simulator.
Also, how much does it cost to hire a Ridley Gain phase analyser?...i can see buy price, but not hire price on the web. With the AP gain phase analyser, we can measure the feedback loop gain and phase margins of the PFC.