LT1054: Bipolar low noise using LT1054

David Smith

Part Number: LT1054
Other Parts Discussed in Thread: TLV61046A,

Hi!

I'm working on a low noise bipolar voltage doubler for a USB device - for approx +/-8V output after voltage drop.

It this something that can simulated (with some injected input votlage noise) using TinaTI or LTspice?

Do you have any information about what value C5 could be to raise the switching frequency above 50kHz, such as 22pF C0G.

Any circuit comments would be welcomed. Diodes are 1N4001.

Thanks!

over 2 years ago

0 David Smith over 2 years ago

Prodigy 220 points

I may also consider a TLV61046A to boost USB vbus to ~ 15V

0 Youhao Xi over 2 years ago in reply to David Smith

TI__Guru 68595 points

Hi David,

Thank you for considering our solutions. Regarding LT1054, very sorry that we don't have a simulation model at this moment. Regarding C5, it will surely increase the switching frequency, but I could not find the info about the exact relationship between C5 and the raised frequency. One thing is clearly mentioned in the datasheet, page 10, that the recommended capacitor range is 5 to 20pF. You may consider to reduce the capacitor to below 20pF.

Regarding TLV61046A, it should support boosting to 15Vout but please also note that there is a switch peak current limit which should not be tripped under min VIN and max output power. Otherwise, you may need to consider a different Boost converter having higher current limit. We have devices having the current limit >5~6A.

Thanks,

Youhao Xi, Applications Engineering