TPS51601A: DC-DC synchronous boost circuit the boost driver TPS51601A no output

Hi

We have received your question and the right application engineer will help you tomorrow.

Regards

Yihe

Hello,

If the power stage is connected do the following:

1- nSKIP tied high

2- Apply the power to VDD pin of TPS51601A before the supply to the power stage

3- Apply PWM signal

4- Make sure the boot capacitor is connected between BST and SW

If the TPS51601A is tested alone:

1- Connect the BST pin to VDD

2- nSKIP tied high

3- Connect SW to GND

4- Apply PWM signal

I googled the SDS17308Q3 but could not find it. You may send me the circuit schematic as well.

Regards

Hello Mahmoud,

Thanks for your above applying note, will try it.

here is the boost schematic what we currently drafted ,pls correct me if you find something wrong(the PACK+ is 4Vdc,we want to boost it to 7Vdc with 200Khz PWM that applied to the boost chip TPS51601A, and the VDD on TPS51601A is 5Vdc,but there no out on both DRVH and DRVL).

the correct No. of N-MOSFET are CSD17308Q3,you can find it on IT weibsite.

Thanks and have a nice weekend!

Peter

Hello Peter,

The boost capacitor is charging during the on time of the lower FET and develops a voltage of VDD (5V) level between BST and SW pins. That means a voltage of 10V between BST and GND. When the upper FET turns on the voltage at SW node is 7V relative to GND and the voltage between the gate and source of the upper FET is 10V - 7V = 3V. 

The configuration of the driver TPS51604 and the power stage looks OK. The recommendation is to power up the driver Vdd before the power stage. Please let me know if you have additional question.

Regards, Mahmoud