TPS65130 - EVM and Modification

Alex52381

Other Parts Discussed in Thread: TPS65130

Hello All,

I recently purchased a TPS65130 EVM from TI. The module is hard wired to support -5V and 8V outputs. I would like to modify the EVM to have an output of +3.3V and -3.3V. However, the EVM's resistor numbering and the datasheet's resistor numbering don't quite match up.

Before I go out and make a parts order, I wanted to know what resistor values TI suggested to make this modification as well as confirm which resistors on the EVM I should modify.

Thanks,

Alex

over 14 years ago

0 Brigitte over 14 years ago

TI__Guru 65200 points

Hello Alex,

Please use formulas 1, 2, 11 and 12 from the datasheet and substitute the resistors and capacitors as given below:
Datasheet = EVM:
R1 = R3
R2 = R4
R3 = R5
R4 = R2
C9 = C6
C10 = C9

It might be helpful to replace R6 in the EVM with a 0 Ohm resistor, but it should work with the given one also.

Best regards,
Brigitte

0 Alex52381 over 14 years ago in reply to Brigitte

Intellectual 810 points

Brigitte,

Thanks for the help. I am looking to use this module to provide power to the + and - supply rails of op amps as well as my ADC in an instrumentation design. Is there a way that I can modify the system to reduce my noise? I understand that I can increase the inductor sizes, or add an LC filter. Based on the TINA TI simulations, I'm not sure if this filtering does enough to suppress the noise.

Thanks,

Alex

0 Brigitte over 14 years ago in reply to Alex52381

TI__Guru 65200 points

Hello Alex,

Measurements showed that best performance for suppressing noise in the power supply are achieved by a ferrite bead with the right frequency band and if necessary a snubber at the switch pin. Please have a look in this application note about these methods: http://focus.ti.com/analog/docs/litabsmultiplefilelist.tsp?literatureNumber=slaa461&docCategoryId=1&familyId=390

Best regards,
Brigitte

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TPS65130 - EVM and Modification