Other Parts Discussed in Thread: LM5088, TINA-TI
I used WEBENCH to create some suggestions for a power supply design that will accept an input voltage of 18V-28V and output +/-17.5V 2.5Amp output rails. The positive rail is straight forward and simulates well. WEBENCH even provided a downloadable simulation for that supply.
The negative rail suggests using the LM5088 configured as an inverting regulator. WEBENCH in this case provides schematic, BOM, simulation operating points and power usage but does not provide a downloadable simulation. So I downloaded the transient model for TINA directly from TI and wired everything up to simulate it. The simulation does not work and I cannot tell if this is a model/simulation problem or a part selection issue or a design issue.
I will try to attach the WEBENCH report and also the TINA model I created, so hopefully that works.
In the TINA model I have it so that you can test it as a positive rail and verify all the values and wiring is correct. Then you can switch the connection for output and ground to get the negative voltage. It does not work (I only get -5V and the switch pattern does not look correct) and would like to know is there a problem using this part to get the negative rail or is this a simulation problem. If I ground RT to 0V ground instead of -17.5V output I can get -20V but either case does not look like its regulating. I am under pressure to fabricate the design but do not want to do so until I can get some more information on why I am not able to correctly simulate it
Thanks for any help!
webench_design_4287691_12_565346599.pdfTINA-LM5088_EXAMPLE.TSC
