TPS54160A: +-18V design to power AMP, please help to check

Yue TANG

Part Number: TPS54160A

Hi,

My customer used TPS54160A to produce +-18V power rail for AMP and asked for a schematic review. I'm not familiar with this usage. Please kindly help to check it . thanks.

24V in +-18V out

over 5 years ago

0 Orlando Murray over 5 years ago

TI__Mastermind 22301 points

Yue,

I will review this and get back to you with feedback this week.

-Orlando

0 Yue TANG over 5 years ago in reply to Orlando Murray

TI__Expert 8705 points

Orlando,

Could this be a bit quick? My customer is also evaluating other device.

0 Orlando Murray over 5 years ago in reply to Yue TANG

TI__Mastermind 22301 points

Hi Yue,

I like this design of fly buck-boost. Here is my feedback:

EN divider will not function like this, needs to be referenced to negative output (AO_-18V).

Feedback resistors set negative VOUT voltage (V-). The feedback resistors should be configured to get 18Vout.

The upper feedback resistor can change to 22kΩ to fix this.

The positive output voltage is set by the transformer turns ratio and the forward drop of the diode.

V+ = ||V-||*(N2/N1) - Vfwd

I would add bypass 0.1µF capacitors on both outputs to GND.

Switching frequency seems set at 309kHz. Resulting primary ripple current is around 220mA. Please confirm.

What is the output current or power? Need to be sure not to exceed current limit of the part.

Hope this helps,

-Orlando

0 Yue TANG over 5 years ago in reply to Orlando Murray

TI__Expert 8705 points

Or'lando,

Thanks for the reply. I'll work with customer. please wait for my further feedback. BTW, is there a ref design for this usage?

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TPS54160A: +-18V design to power AMP, please help to check