Hello,
I am trying to set up a switching regulator to supply 5V from a varying input source, but I am having some issues. The regulator IC I am using is the LM2672 (datasheet)
Under a small load (for example a microcontroller), the circuit regulates the voltage very nicely throughout the range of input voltages. However, as I try to apply a larger load (~250 mA at 5V with some resistors), the circuit only regulates the voltage decently with an input of ~6.8V. As I increase the input voltage from there, the output voltage drops down to 2-3V.
What could be going wrong?
I have tried to follow the datasheet, and I have tried various combinations of components as given by the datasheet. I have tried using a 47μH inductor as well as a 68μH inductor. The catch diode is a 1N5817, and the output capacitor is a low ESR 100μF. At the input end I have a low ESR 330μF capacitor.
This setup should handle significantly higher output currents than I'm trying to use. Is there something from the datasheet that I have overlooked, or some other mistake I might have made?
Thanks in advance
I am trying to set up a switching regulator to supply 5V from a varying input source, but I am having some issues. The regulator IC I am using is the LM2672 (datasheet)
Under a small load (for example a microcontroller), the circuit regulates the voltage very nicely throughout the range of input voltages. However, as I try to apply a larger load (~250 mA at 5V with some resistors), the circuit only regulates the voltage decently with an input of ~6.8V. As I increase the input voltage from there, the output voltage drops down to 2-3V.
What could be going wrong?
I have tried to follow the datasheet, and I have tried various combinations of components as given by the datasheet. I have tried using a 47μH inductor as well as a 68μH inductor. The catch diode is a 1N5817, and the output capacitor is a low ESR 100μF. At the input end I have a low ESR 330μF capacitor.
This setup should handle significantly higher output currents than I'm trying to use. Is there something from the datasheet that I have overlooked, or some other mistake I might have made?
Thanks in advance