A Review of Charge Pump Topologies for the Power Management of IoT Nodes

Abstract

With the aim of providing designer guidelines for choosing the most suitable solution, according to the given design specifications, in this paper a review of charge pump (CP) topologies for the power management of Internet of Things (IoT) nodes is presented. Power management of IoT nodes represents a challenging task, especially when the output of the energy harvester is in the order of few hundreds of millivolts. In these applications, the power management section can be profitably implemented, exploiting CPs. Indeed, presently, many different CP topologies have been presented in literature. Finally, a data-driven comparison is also provided, allowing for quantitative insight into the state-of-the-art of integrated CPs.

A simple and effective design strategy to increase power conversion efficiency of linear charge pumps

“…To validate the proposed design strategy, extensive simulations have been carried out on two‐, four‐, six‐, and eight‐stage cross‐coupled CPs (also referred in literature as latched CPs) implemented in a standard 65‐nm CMOS technology.…”

“…Finally, I L represents the output current supplied to the load. In practical implementations, diodes are substituted by a simple diode-connected transistors or, more frequently, by combinations of MOSFETs to get rid of the voltage drop, V Th , of each CTS [2][3][4] The power consumption of the CP in steady-state condition can be expressed by*…”

“…Therefore, they are suitable to be fully integrated and have been widely used in solid‐state electronic systems since 1976 . The field of application of CPs is very wide and include nonvolatile memories and SRAMs, RF antenna switch controllers, LCD drivers, and, more recently, power management ICs (PMIC) for internet of thing (IoT) nodes In this latter context, the design of a CP is a challenging task since it must work with very low input voltage supply (few hundreds of millivolts) and high‐power conversion efficiency, while delivering few milliwatts of power to the load.…”

Current‐mode body‐biased switch to increase performance of linear charge pumps

“…Charge pump (CP) circuits fall into the class of the on‐chip voltage generators. Since their simple topologies are made‐up by switches and capacitors, they are amenable to be fully integrated and have been widely used in solid‐state electronic systems since the early 70s 1–4 . CPs are exploited in a large amount of applications, such as nonvolatile memories, SRAMs, switch controllers, LCD drivers and, more recently, energy harvesters 5–14 .…”

Linear distribution of capacitance in Dickson charge pumps to reduce rise time

“…Charge pump (CP) circuits are commonly applied to generate voltages higher than the power supply and, in their integrated version, are realized by using only metal‐oxide‐silicon (MOS) transistors, used as switches or diodes, and capacitors. Among the several CP topologies, the well‐known Dickson CP is the first integrated version and represents the most adopted and advantageous solution for memory applications.…”