TPS65131: Issues with TPS65131 in generating asymmetrical power supply

Hi Team,

Our customer design using TPS65131 is experiencing issues in generating asymmetrical power supply.

According to our customer, when the negative rail is loaded, with even a small load it begins to oscillate quite badly.
Here's the schematic of the design:
(Deleted attachment)

List of alterations. 1. I replaced U3 with an LM2842 2. I replaced C10, C11 with a single 33 uF capacitor 3. I removed L5, L6, C7, C8 and R19, R20 (the LRC filters on the outputs of the asymmetrical PSU).

The problem occurs when they have the OPA2197 in circuit, otherwise, they get the rails as intended. +10 and -5

Here's the scope image from the customer:


The customer already done pin by pin comparison and checked the schematic vs TPS65131 schematic.

Please let me know your comment or if you have other questions.

Thanks,

Jonathan