TPS63070: pls recommend the most suitable solution for buck boost

add more critiria,

1. Vin min: < 3.5V 

2. Vin max: > 15V

3. Vout can cover from 3.5V to 5V

4. Iout max: 2.5A to 3A

5. switching frequency > 1MHz

6. Good thermal resistance (junction to ambient)  < 70degC/W

7. good line/load transient response

6. Small package

Hi Bonnie,

The closest fit is the TPS63070. 

1. Vin,min = 3 V for startup, Vin,min = 2 V after startup.
2. Vin,max = 16 V.
3. Vout can go from 2.5 V to 9 V
4. At Vout = 3.5 V it can support Iout > 2.5 A for Vin > 3.5 V and Iout = 3 A for Vin > 4.5 V.
   At Vout = 5 V is can support Iout > 1.8 A for Vin > 3.5 , Iout > 2.5 A for Vin >  4.5 V, and Iout = 3A for Vin > 5.5 V.
5. It has fixed switching frequency of 2.4 MHz
6. Rja = 63 K/W,
7. Do you have any criteria for line/load performance?
8. QFN package.

Best regards,
Milos

Hi Milos,

For the point #4, let me be more specific.

Our Vout is planned to set at 3.7V. Also, the Vin may range from 3.5V to 5.25V, due to power cable loss or compatibility for different power adapter.

Could TI give a promise that with Vin from 3.5V to 5.25V, the Iout can always work more than 2.5A?  

Hi Bonnie,

Then I will repeat the measurement specifically for Vout = 3.7 V. At this output voltage I think it will be tight, and the maximum output current will be somewhere between 2 A and 2.5 A. But I will let you know today.

In the meantime, just two additional notes, let me know if you have comments for these:

• These tests will be done on the TPS63070 EVM, at ambient temperature. For different PCB layouts, and different operating conditions (in the first place temperature), the results will be different. Higher temperature - lower maximum output current.
• This is the maximum output current once the device starts up. The device is not able to start up if the maximum output current is immediately present during the startup.

Best regards,
Milos

Hi Milos,

do you have update on this? thanks!

Hi Bonnie,

We haven’t heard back so we're assuming this resolves your issue. If not, just post a reply below, or create a new thread if the thread has locked due to time-out.

Thanks and regards,
Milos