TPS61194-Q1: Boost Start time is 0.5ms instead of 50ms

Alan Wiseman

Part Number: TPS61194-Q1
Other Parts Discussed in Thread: TPS61194,

When I enable power to my TPS61194, and enable (pin 4) is set to 3V3, the BOOST converter starts in 0.5ms instead of the 50ms claimed in the data sheet, Figure 18.

In the figure below,

Channel 1 is the input power, 12V.

Channel 2 is the boost converter output.

There is a delay of approximately 65ms from applying power to the converter starting. This is the device soft start time. There should then be a 50ms window where the boost converter starts up. In the figure below, the boost converter starts in approximately 0.5ms. This causes an inrush current large enough to trip our load switch and so the input voltage is turned off. I have tested this on an eval card and the eval card behaves the same. Can somebody tell my why I do not have a boost start time of 50ms

Thanks

over 8 years ago

0 Clancy Soehren over 8 years ago

TI__Mastermind 23810 points

Alan,

I am moving this to the LED driver forum. They should be able to answer your question there.

Thanks,

-Clancy

0 Liaqat Khan over 8 years ago in reply to Clancy Soehren

TI__Mastermind 18550 points

Hi Alan,
Figure 18 is state transition diagram of the device and 50ms mentioned there is unfortunately a typographic error.
For boost start timing, you can look at the scope plot in figure 23 which shows similar timing as what you measured. So what you are measuring is the normal startup behavior for TPS61194-Q1.
Hope this clarifies but please let me know if there are any other questions.
Regards,
Liaqat

Power management

Power management forum

TPS61194-Q1: Boost Start time is 0.5ms instead of 50ms