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Design >> High-Power Design >> Generate two high voltage levels in parallel
https://designers-guide.org/forum/YaBB.pl?num=1467192713

Message started by bki on Jun 29^th, 2016, 2:31am

Title: Generate two high voltage levels in parallel
Post by bki on Jun 29^th, 2016, 2:31am

Hi,

i need to generate two voltage levels in parallel by using only 1 inductor: 40V and 20V

The idea was to generate 40V out of 5V (supply) with a boost converter and then bring the 40V down to 20V by use of an LDO...but the LDO has very bad Efficiency for this Operation (lage negative gain).

I have other ideas in mind like:
1. generating 20V with the boost converter and then use a switched capacitor circuit to double the voltage to 40V

2. harvest the energy anyhow from the LDO to not waste too much energy

Solutions with inductor like step-down converter is NOT an Option.

What do you think about it? What are your ideas for implementation?

Title: Re: Generate two high voltage levels in parallel
Post by loose-electron on Jul 6^th, 2016, 10:43pm

Create the 40V

Take the 40V and drive a switch at 50% duty cycle
Low pass filter
Output = 20V

Or:

Create the 20V
Take the 20V and use it to power a switched capacitor charge pump
Output = 40V

Neither method uses an inductor.