TPS61090 start up issues

Q: TPS61090 start up issues by 741196



Customer is using the TPS61090 to generate 5V to charge cell phones.

One of the cell phones require 1A charging current.

Once the TPS61090 is waking up to this load, obviously it enters to current limit and “stuck’ on 2.5V.


One of the solutions that can work is to enable the load only after the regulator charge the output capacitor to the required output voltage.


Do we have other ways to handle this issue? Better ones?


I saw that the TPS61175 doesn’t have this current limit at start up. At least it doesn’t mentioned in the datasheet.

Could you confirm this that TPS61175 knows to wake up to heavy load?





Amit Benjamin,
Analog & Power FAE
Texas Instruments, Israel,
Cell     +972 54 6663791




A: Re: Powermat - TPS61090 start up issues by 10449

The TPS61090 has the well known "boost softstart" issue.  You are correct that the solution is to let the IC's output voltage go into regulation before applying full load.  The TPS61175 will startup into full load.