High efficiency charge-and-add adjustable DC-DC converter
View Patent ↗A charge-and-add DC-DC voltage converter design using a switch network that toggles between two states, either simultaneously charging a flying capacitor (one or any number) or creating a DC voltage on the output capacitor by connecting all flaying capacitors in series thus adding the input voltage to remaining voltages on flying capacitors after they were charged. A pulse generator delivers a train of pulses to toggle the switch network. Depending on the applications, the train of pulses can be continuous when a fixed unregulated voltage must be delivered, or a defined number of pulses when voltage (power) surge is to be produced. The charge-and-add converters should be capable of delivering a regulated output voltage, and in this case, pulse-width modulation (PWM) or pulse frequency modulation (PFM) can be used.
1. A DC-DC voltage converter comprising:
a plurality of flying capacitors;
a plurality of electronic switches, wherein each of said switches has a first switch position and a second switch position;
an output capacitor coupled to a load;
a pulse generator driving said plurality of electronic switches with a pulse train so that said switches toggle between said first switch position and said second switch position;
wherein said flying capacitors each charge to an input voltage value in said first switch position; and
wherein said flying capacitors are connected in series in said second switch position to deliver an output voltage to said load, said output voltage being higher than said input voltage;
and wherein each of said switches is a high-speed SPDT solid-state switch module.
2. The DC-DC converter of claim 1 wherein said pulse train is pulse-width modulated (PWM).
3. The DC-DC converter of claim 1 wherein said pulse train is pulse-frequency modulated (PFM).
4. The DC-DC converter of claim 3 wherein said pulse train is produced by a voltage controlled oscillator (VCO).
5. The DC-DC converter of claim 1 wherein each of said switches contains at least one MOSFET transistor.
6. A DC-DC voltage converter comprising:
a plurality of flying capacitors;
a plurality of electronic switches, wherein each of said switches has a first switch position and a second switch position;
an output capacitor coupled to a load;
a pulse generator driving said plurality of electronic switches with a pulse train so that said switches toggle between said first switch position and said second switch position;
wherein said flying capacitors each charge to an input voltage value in said first switch position; and
wherein said flying capacitors are connected in series in said second switch position to deliver an output voltage to said load, said output voltage being higher than said input voltage;
wherein said pulse generator delivers either pulse-width modulated (PWM) or pulse frequency modulated (PFM) pulses;
and wherein each of said switches is a high-speed SPDT solid-state switch module.
7. The DC-DC converter of claim 6 wherein each of said switches contains at least one MOSFET transistor.
8. The DC-DC converter of claim 6 wherein said PFM pulses are supplied from a voltage controlled oscillator (VCO).