Tool/software:
My circuit is built using a TPS65131 to output ±15V with a 5V input.(Target current +160mA,-140mA)
My circuit is created as shown in figure 8-1(Typical Application) in the data sheet.
The values of the components
R1=600kΩ
R2=52.8kΩ
R4=48.5kΩ
R3=600kΩ
C9=10P
C10=10P
Other values are the same as in Figure 8-1
Enter high level for PSN,PSP
Since the output voltage was about -23V when there was no series resistor at C10, a series resistor of 56KΩ was added.
(Equivalent to R6 in series with C9 in the TPS65131EVM schematic)
A 56KΩ series resistor was also added to C9.
When the load current is ±230 mA, the output ripple is small and operates correctly.
When operated at the target current (+160mA, -140mA), a large oscillation (about 10kHz centered at -15V, 400mVP-P, triangular wave) occurs at the - side output.
(Positive,Negative switching action is no pulse skip)
When a 2KΩ resistor is placed in series with C10, it now operates correctly up to -115mA, with low output ripple.
(If the positive side is pulse-skipped, the negative side is also affected, so the positive side operates with a load that is not pulse-skipped.)
When the - side load is operated at -100mA, a large oscillation (about 10kHz centered at -15V, 200mVP-P, triangular wave) occurs at the - side output.
(Positive side: A 2KΩ series resistor was also added to C9. Load 150mA No pulse-skipping operation.)
How can I prevent oscillation when the load is between ±50mA and ±150mA? (except during pulse skipping)
