The simplest switched-capacitor (SC) circuit is made of one capacitor and two switches S1 and S2 which alternatively connect the capacitor to either in or out at a switching frequency of. Recall that can express the relationship between voltage, current, and resistance as:.
What is a switched capacitor?
A switched capacitor (SC) is an electronic circuit that implements a function by moving charges into and out of capacitors when electronic switches are opened and closed. Usually, non-overlapping clock signals are used to control the switches, so that not all switches are closed simultaneously.
The simplest switched-capacitor (SC) circuit is made of one capacitor and two switches S1 and S2 which alternatively connect the capacitor to either in or out at a switching frequency of . Recall that Ohm's law can express the relationship between voltage, current, and resistance as:
What is a switched capacitor inverter?
Switched capacitor inverters are low cost and compact and are capable of achieving efficiencies greater than 90%. Obviously, the current output is limited by the size of the capacitors and the current carrying capacity of the switches. Typical IC switched capacitor inverters have maximum output currents of about 150mA maximum.
Are multi-layer ceramic capacitors useful for switching power supply circuits?
In recent years, multi-layer ceramic capacitors (MLCCs) have often been used as the input and output capacitors of switching power supply circuits. Although MLCCs, which feature excellent ESR and ELS characteristics, are useful for switching power supplies, they are not without their issues such as large capacity, quantity, and costs.
How do you regulate a switched capacitor converter?
There are three general techniques for adding regulation to a switched capacitor converter. The most straightforward is to follow the switched capacitor inverter/doubler with a low dropout (LDO) linear regulator. The LDO provides the regulated output and also reduces the ripple of the switched capacitor converter.
Why are hybrid capacitors used in power supply circuits?
In both cases of input and output capacitors, the switching frequency range of power supply circuits was 100 kHz - 300 kHz, and the configuration with hybrid capacitors was able to achieve impedance and ESR values equal to or lower than those of the original configuration with MLCCs. This was the reason that made these replacements possible.