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Design >> High-Power Design >> how to make a soft-start in charge pump
https://designers-guide.org/forum/YaBB.pl?num=1235812674

Message started by hdqkwr on Feb 28^th, 2009, 1:17am

Title: how to make a soft-start in charge pump
Post by hdqkwr on Feb 28^th, 2009, 1:17am

Hi,all:
In a charge pump DC-DC converter, how to make a soft-start in it?As in start up time, there is large inrush current exist in charge pump.I want to get some way to suppress it, is there any reference or any suggestion?

Title: Re: how to make a soft-start in charge pump
Post by NiceFeng on Apr 12^th, 2009, 5:11am

hdqkwr wrote on Feb 28^th, 2009, 1:17am:

Hi,hdqkwr,

During start-up period, you could operate some of the power switches as current source, which means connected the gate voltage to a biasing voltage instead of Vdd/GND.

Feng

Title: Re: how to make a soft-start in charge pump
Post by mengcy on Mar 18^th, 2010, 7:15pm

Hi, do you integrate a short circuit protection or current limiting block on your chip?
If the answer is yes, you can reuse the protection circuit to control the startup current.

Title: Re: how to make a soft-start in charge pump
Post by RobG on Feb 22^nd, 2011, 12:00pm

NiceFeng wrote on Apr 12^th, 2009, 5:11am:

hdqkwr wrote on Feb 28^th, 2009, 1:17am:

Hi,hdqkwr,

During start-up period, you could operate some of the power switches as current source, which means connected the gate voltage to a biasing voltage instead of Vdd/GND.

Feng

This is easy to do... see Fig. 12 of Gregoire, "A compact switched-capacitor regulated charge pump power supply," JSSC, Aug 2006, 1944-1953

Title: Re: how to make a soft-start in charge pump
Post by Kevin Aylward on Jul 6^th, 2013, 8:35am

Large RC time constant on the reference voltage to the converter.