Hello,
I am using the TPS723 as a negative regulator to take a -9V unregulated input and step it down (in magnitude) to -5V. I have a value for R1 of 100k and R2 is 32k. The measured DC output voltage is correct (about -5.16V), but there is a ~1Vpp ~1kHz oscillation at the output, which smells like a stability problem. I can hear the ceramic cap at the output scream. What am I doing wrong? Is the 10uF cap at the output too large? I tried swapping out C5 for a small 1uF cap, but still have the same issue. I also tried swapping out the TPS723 for a different IC, but still, have the same issue.
Fig. 1. Schematic for TPS723
Fig 2. Output voltage (AC-coupled). DC Voltage is -5.16V.
Best,
Jordan
