TPS56339: Asking for the recommendation on the TPS54302 and TPS56339 design detail

SHH

Mastermind 31246 points

Part Number: TPS56339
Other Parts Discussed in Thread: TPS54302

Hi Team,

Customer is looking for solution to replace competitor for 24V/3A application. The Vout might be 3.3V, 5V and 10V

Would you please recommend for the following questions?

Can TPS54302 and TPS56339 support CCM and DCM mode?
Can TPS54302 and TPS56339 support t COT mode? Will the light load switching frequency in audio band to generate the noise?
If audio noise might happened in the specific, then how to modify the circuit at the inductor or cap?

BR,

SHH

over 5 years ago

0 Shawn Nie over 5 years ago

TI__Genius 10070 points

Hi,

1. Yes, TPS54302 and TPS56339 support CCM and DCM mode, it is Eco-mode at light load.

2. TPS54302 and TPS56339 are not COT mode device. And at light load, the switching frequency is reduced. There is no OOA function.

3. What is the reason for audio noise? Switching frequency is lower than 20kHz or beat interference?

Shawn

0 SHH over 5 years ago in reply to Shawn Nie

TI__Mastermind 31246 points

Hi Shawn,

the application has the analog amp to drive the speaker.

So RD need to consider the light load condition's PWM modulation. if the switching frequency is within 20Hz~20KHz range, what is the usually way to modify the circuit?

BR,

SHH

0 Shawn Nie over 5 years ago in reply to SHH

TI__Genius 10070 points

Hi,

For current mode device, reducing the inductance can increasing the switching frequency at light load.

Shawn

0 SHH over 5 years ago in reply to Shawn Nie

TI__Mastermind 31246 points

Hi Shawn,

thanks for feedback.

would you please let me know where to tell CCM or DCM in datasheet? how to switch CCM and DCM if support both?

Do you have any document or basic video explanation about CCM, DCM and COT? What is OOA?

BR,

SHH

0 SHH over 5 years ago in reply to SHH

TI__Mastermind 31246 points

Hi Shawn,

Would you please provide your comment?

BR,

SHH

0 Shawn Nie over 5 years ago in reply to SHH

TI__Genius 10070 points

Hi,

CCM means the converter works on the discontinuous conduction mode, DCM means discontinuous conduction mode.

COT means constant on time.

OOA means Out-of-Audio.

Below files are for your reference.

http://www.ti.com/lit/an/slva057/slva057.pdf?keyMatch=SLVA057&tisearch=Search-EN-technicaldocument

http://www.ti.com/lit/an/slua946/slua946.pdf?keyMatch=DYNAMICALLY%20CONTROL%20THE%20OUTPUT%20VOLTAGE&tisearch=Search-EN-technicaldocument

Shawn

Power management

Power management forum

TPS56339: Asking for the recommendation on the TPS54302 and TPS56339 design detail