Scalable switched capacitor integrated buck (SCIB) regulator for high conversion step down application
Described herein is a technology for implementing a scalable SCIB regulator for high conversion step down application. Particularly, the SCIB is configured to include stacked input switch circuits with parallel-connected output switch circuits. The input switch circuits are stacked with or without DC shift switch circuits in between. Furthermore, the input voltage is stepped down to a biasing voltage by input switch circuits and then is regulated to one or more output voltages having one or more independent and predetermined values by output switch circuits. The input switch circuits, output switch circuits and DC shift switch circuits can be modified for scalable power capability and ease of control and manufacturing.
1. A voltage step down dc-dc converter comprising:
first and second input switch circuits, the first input switch circuit coupled to an input terminal, and the first and second input switch circuits configured to step down an input voltage at the input terminal to a biasing voltage;
first and second output switch circuits connected in series with the first and second input switch circuits respectively, the first and second output switch circuits comprising respective first and second buck regulator circuits having respective first and second voltage outputs, and the first and second buck regulator circuits configured to regulate the biasing voltage to different output voltages at the first and second voltage outputs; and
a DC shift switch circuit coupled in series between the first and second input switch circuits, the DC shift switch circuit configured to compensate voltage differences between the first and second input switch circuits.
2. The voltage step down dc-dc converter of claim 1 , wherein the first and second buck regulator circuits are configured to regulate the biasing voltage to different output voltages below the input voltage.
3. The voltage step down dc-dc converter of claim 1 , wherein the voltage step down dc-dc converter is controlled by a single-phase buck controller or a multi-phase interleaved buck controller.
4. The voltage step down dc-dc converter of claim 1 , wherein the input voltage is a voltage from 4 to 60 volts, and the different output voltages are voltages from 0.5 to 15 volts.
5. The voltage step down dc-dc converter of claim 1 , wherein each of the first and second input switch circuits comprises:
a respective high-side switch and a respective low-side switch connected in series;
wherein the high-side switch is connected to either an input capacitor or a common node of a middle capacitor and another input switch circuit, and
the low-side switch is connected to either a biasing voltage capacitor or a common node of a middle capacitor and another input switch circuit, and
a common node of the high-side switch and the low-side switch is connected to a corresponding flying capacitor.
6. The voltage step down dc-dc converter of claim 1 , wherein each of the first and second output switch circuits comprises:
a respective low-side switch; or
a respective high-side switch and a respective low-side switch connected in series;
wherein the high-side switch is connected to a biasing voltage capacitor, and the low-side switch is connected to ground, and
the low-side switch is connected to either an inductor or a common node of an inductor and a flying capacitor, and
the flying capacitor is connected to the first or second input switch circuit, and the inductor is connected to an output capacitor.
7. The voltage step down dc-dc converter of claim 5 or 6 , wherein the voltages of the capacitors are inherently balanced and steady at voltages that are proportional to the input voltage.
8. The voltage step down dc-dc converter of claim 1 , wherein each of the first and second input switch circuits or each of the first and second output switch circuits has an inherent capability of zero voltage switching or zero current switching.
9. The voltage step down dc-dc converter of claim 1 , wherein the DC shift switch circuit comprises:
a high-side switch and a low-side switch connected in series; or
a high-side switch, a low-side switch and a floating switch connected in series; or
a high-side switch, a low-side switch, a floating high-side switch and a floating low-side switch connected in series.
10. A scalable switched capacitor integrated buck (SCIB) regulator comprising:
first and second input power stages, the first input power stage coupled to an input terminal, and the first and second input power stages configured to step down an input voltage at the input terminal to a biasing voltage;
first and second output power stages connected in series with the first and second input power stages respectively, the first and second output power stages comprising respective first and second buck regulator circuits having respective first and second voltage outputs, and the first and second buck regulator circuits configured to regulate the biasing voltage to different output voltages at the first and second voltage outputs; and
a DC shift switch circuit coupled in series between the first and second input power stages, the DC shift switch circuit configured to compensate voltage differences between the first and second input power stages.
11. The SCIB regulator of claim 10 , wherein the input voltage is a voltage from 4 to 60 volts, and the different output voltages are voltages from 0.5 to 15 volts.
12. The SCIB regulator of claim 10 , wherein each of the first and second input power stages or each of the first and second output power stages comprises a respective high-side switch and a respective low-side switch connected in series and a respective half bridge gate driver.
13. The SCIB regulator of claim 10 , wherein the DC shift switch circuit comprises:
a power stage; or
a power stage and a floating switch connected in series; or
two power stages connected in series.