Other Parts Discussed in Thread: TPS82130, , TINA-TI
Tool/software: WEBENCH® Design Tools
The WEBENCH Design tools don't seem to permit creation of an inverting buck-boost circuit using the TPS82140. However the datasheet shows this configuration as an example circuit and the higher current TPS82130 has an eval board and app-note using this configuration.
I exported a standard buck configuration from WEBENCH into TI-Tina and modified it to an inverting buck-boost as per the TPS82130 app note but it doesn't operate as expected, and I'm not sure if this is a problem with the model or my inexperience with TI-Tina. The transient simulation runs but I get no output and a very large current flows from the Vin to ground suggesting the 82140 isn't switching.tps82140_inv_buck_boost.tsc