What is a charge pump voltage doubler?
1 Answer
A charge pump voltage doubler is an electronic circuit that doubles the input voltage using a capacitive charge transfer technique. It's a type of voltage multiplier that provides an output voltage that is approximately twice the value of the input voltage.
The basic charge pump voltage doubler circuit consists of two capacitors, two diodes, and two switches. The switches are typically implemented as transistors. The circuit operates in two phases:
Charging Phase: During this phase, one capacitor is connected to the input voltage, and the other capacitor is connected to the ground. The two switches alternate between being closed and open. When a switch is closed, the corresponding capacitor charges to the input voltage. When the switch is open, the charged capacitor retains its voltage.
Doubling Phase: In this phase, the charging process is reversed. The switches now alternate between being open and closed. The capacitor that was previously charged to the input voltage is now connected in series with the input voltage, effectively doubling the voltage across the load.
By employing this charge transfer mechanism between the capacitors, the charge pump voltage doubler can effectively double the input voltage. However, it's important to note that the actual output voltage may not be exactly twice the input voltage due to losses and imperfections in the circuit. Efficiency and output voltage stability can be improved through circuit design and component selection.
Charge pump voltage doublers are commonly used in low-power applications, such as in some portable devices and energy harvesting systems, where a higher voltage is needed from a low-voltage power source without the use of bulky and expensive transformers or inductors.
The basic charge pump voltage doubler circuit consists of two capacitors, two diodes, and two switches. The switches are typically implemented as transistors. The circuit operates in two phases:
Charging Phase: During this phase, one capacitor is connected to the input voltage, and the other capacitor is connected to the ground. The two switches alternate between being closed and open. When a switch is closed, the corresponding capacitor charges to the input voltage. When the switch is open, the charged capacitor retains its voltage.
Doubling Phase: In this phase, the charging process is reversed. The switches now alternate between being open and closed. The capacitor that was previously charged to the input voltage is now connected in series with the input voltage, effectively doubling the voltage across the load.
By employing this charge transfer mechanism between the capacitors, the charge pump voltage doubler can effectively double the input voltage. However, it's important to note that the actual output voltage may not be exactly twice the input voltage due to losses and imperfections in the circuit. Efficiency and output voltage stability can be improved through circuit design and component selection.
Charge pump voltage doublers are commonly used in low-power applications, such as in some portable devices and energy harvesting systems, where a higher voltage is needed from a low-voltage power source without the use of bulky and expensive transformers or inductors.