TPS1211-Q1: The output of TPS1211-Q1 when used for power switch

Suy,

Are you talking about a 500ns period (in other words, 5MHz)?

We would not be able to switch this fast- but our PWM frequency would be able to reach close to 500Khz with an external supply for the BST capacitor:

Best Regards,
Tim 

Hi Tim ，

I mean the duration of the high level of the control signal of the INP, and the period is less than 100Khz.

In other words I want to get a pulse output of Vout.

Suy,

If we power the CBST with external supply, we can switch at very high frequency.

The turn-off time are in the order of 1us so, we can switch comfortably up to 500kHz.

Best Regards,
Tim

Hi Tim，

I put EN to high level,put the INP as a pulse signal(The switching frequency is 10Khz),but the output of PU&PD is unnormal, please look the picture(MOSFET NC):

Suy,

Is the BST capacitor powered by an external source with a diode connected to as mentioned previously? This would be a major gating factor here.

Best Regards,
Tim 

Hi Tim，

Below is my circuit diagram.

 I have a question is  when the VCC_aux is powered by the external source，is it must higher than the VCC_tx?

When i powered VCC_aux by an external  12V,the width of the INP must be set to more than 500ns (signal period is 200us), PD&PU have output, but the output is not output every cycle and the base of the signal is always changing, please see the picture below:

Hi Tim，

Please look at my last post，the output signal of PD&PU I tested looks abnormal, could you please help me find out what the problem is？

Suy,

12V should be sufficient for the VAUX connection on the BST capacitor. 

What is the blue line in the following graph? 

It looks like there might be some inrush capacitance that is possibly triggering a fault. What is exactly on the load- is it a real load or an eLoad?

Best Regards,
Tim

Hi Tim，

The blue line in the graph is the output of PU&PD when the mosfet is not paste.

In other words, the tps1210 did not have any load when I measured the output of the PD&PU