High-Efficiency Charge-Pump Circuits which Use a 0.5V_(dd)-Step Pumping Method

摘要

This paper presents a 0.5V_(dd)-step pumping method for Dickson-type charge-pump circuits that achieve high overall efficiency, including regulator circuitry, even at large output currents, and these circuits are targeted at mobile equipment applications. We have designed positive and negative charge-pump circuits which use a 0.5V_(dd)-step pumping method, are implemented with advanced control functions, and are fabricated with our custom CMOS process. Measured results showed that efficiency of a 2.5-stage positive charge-pump circuit before regulation is more than 93% (power supply V_(dd) = 5 V, output voltage V_(out) = 16.9V ≒ 3.5V_(dd), output current I_(out) = 4mA), and that of a 1.5-stage negative charge-pump circuit is 93% (power supply V_(dd) = 5 V, output voltage V_(out) = -7.2V ≒ -1.5V_(dd), output current I_(out) = 4mA).