Charge Pump Switches

Charge pump switches are semiconductor-based switching devices integrated within charge pump circuits, which are DC-DC converters that use capacitors to store and transfer charge. These switches control the timing and sequence of capacitor charging and discharging phases, enabling efficient voltage multiplication, inversion, or regulation without inductors. They are critical for managing power delivery in low-power and space-constrained applications, such as in integrated circuits, where they facilitate functions like voltage boosting for displays or biasing in analog circuits.

Charge pump switches operate by alternately connecting capacitors to input and output voltages in a controlled sequence. During the charging phase, switches close to connect capacitors to the input voltage, storing charge. In the transfer phase, switches reconfigure to connect capacitors in series or parallel with the output, transferring stored charge to achieve desired voltage levels (e.g., doubling or inverting). This switching is typically driven by clock signals from oscillators, with MOSFETs (like NMOS or PMOS) serving as the switch elements due to their fast switching speeds and low on-resistance, minimizing power loss.