Part Number: LM5118
I am using the LM5118 as a phantom power supply in an audio application. The power supply circuit has the following specifications:
Vin = 5V
Vout = 52V
I(min) = 2.2mA
I(max) = 10mA
Switching Frequency = 400kHz
The circuit also has an LDO that drops the 52V to 48V. Then I have a switch that will apply the 48V to power an LED and a condenser microphone. I used a design from Webench which does provide me with 52V under no load.
However, when a load is applied, in this case just the LED which is only using 2.2mA, the output of the LM5118 drops to 42V.
I have tried using various inductor values and the corresponding comp loop values with no success.
I am not sure why this circuit can't keep up with such a small load?