LM2705: feedback resistor selection used for 5V to 13.5V booster

Wentong Liu

Prodigy 30 points

Part Number: LM2705
Other Parts Discussed in Thread: TLV61046A, TPS61046

I got data sheet but not found it mentioned about feedback resistor selection.

I reference figure 12, typical 20-V application.

Vin will be 5V from USB port directly.

Vout 13.5V/50mA for OLED power supplier.

Icl 125mA

Toff 350ns

Then what value of R1, R2 will be?

Wentong, 12/19 18'

over 5 years ago

0 Jasper Li over 5 years ago

TI__Mastermind 46905 points

Hi Wentong,
this LM2705 can't support 50mA output current, because its inductor peak current is only 125mA.
for your application, I would suggest TLV61046A or TPS61046.

The selection of the feedback resistor is determined by the device's reference voltage. a method to select them can be found in the TLV61046A or TPS61046 datasheet.

0 Wentong Liu over 5 years ago in reply to Jasper Li

Prodigy 30 points

Hi Jasper,

Thanks for your help. I would try TLV61046A then.

Wentong, 12/21 18'

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LM2705: feedback resistor selection used for 5V to 13.5V booster