I've been working on a project that requires a 12V and 3.3V supply. The 12V is used for various sensors and an OLED main power while the 3.3V is utilized by an AVR microcontroller and associated logic for the OLED/User input. Currently the power source is 4xAA batteries in series for a total 6V power.
The issue I'm running into is a very large ripple (2Vp-p) on the 'regulated' switching boost regulator. I'm utilizing a LM2733 to boost from the AAs to 12V, following the specifications in the datasheet. With no load, the regulator produces a fairly clean 12V output, but at full load the ripple emerges.
While exploring the problem I've tried setting up a zener diode shunt regulator to limit the noisy 12V signal to 11V which produces a clean 11V unloaded voltage, but upon loading the voltage drops to 7.5V steady.
This same effect is seen when I wired together an Op-amp peak detector to the output; clean 12V with no noise unloaded, and ~7V loaded.
These voltage drop-off lead me to believe the load current required exceeds that which the 4xAA batteries can supply. However, with just the LM2733 switching regulator a similar voltage drop is not seen, just the large voltage ripple.
I do not, unfortunately, have a variable power supply to test the circuit on to see if it relates to the batteries. Also, due to the complexity of the circuit predicting equivalent load resistance to arrive at current requirements would be a difficult task.
Any ideas/recommendations?
The issue I'm running into is a very large ripple (2Vp-p) on the 'regulated' switching boost regulator. I'm utilizing a LM2733 to boost from the AAs to 12V, following the specifications in the datasheet. With no load, the regulator produces a fairly clean 12V output, but at full load the ripple emerges.
While exploring the problem I've tried setting up a zener diode shunt regulator to limit the noisy 12V signal to 11V which produces a clean 11V unloaded voltage, but upon loading the voltage drops to 7.5V steady.
This same effect is seen when I wired together an Op-amp peak detector to the output; clean 12V with no noise unloaded, and ~7V loaded.
These voltage drop-off lead me to believe the load current required exceeds that which the 4xAA batteries can supply. However, with just the LM2733 switching regulator a similar voltage drop is not seen, just the large voltage ripple.
I do not, unfortunately, have a variable power supply to test the circuit on to see if it relates to the batteries. Also, due to the complexity of the circuit predicting equivalent load resistance to arrive at current requirements would be a difficult task.
Any ideas/recommendations?