Hello,
Does this 5W SEPIC LED driver have a poor phase margin.?
The LED current oscillates at ~500Hz (loop crossover frequency) during start-up, as it rises upwards, -however, there is absolutely no LED current overshoot, and the LED current never oscillates when it gets near its regulation value of 50mA.
The LED driver spec is:
Vin = 12V
Vout = ~97V
I(LED) = 50mA
Constant off time
Fsw = 88KHz when in regulation (50mA)
Attached is the schematic ,LTspice simulation, and waveform of LED current and output voltage at start-up
Does this 5W SEPIC LED driver have a poor phase margin.?
The LED current oscillates at ~500Hz (loop crossover frequency) during start-up, as it rises upwards, -however, there is absolutely no LED current overshoot, and the LED current never oscillates when it gets near its regulation value of 50mA.
The LED driver spec is:
Vin = 12V
Vout = ~97V
I(LED) = 50mA
Constant off time
Fsw = 88KHz when in regulation (50mA)
Attached is the schematic ,LTspice simulation, and waveform of LED current and output voltage at start-up