A regulated charge pump for injecting floating-gate transistors

Floating-gate transistors have found many applications in both analog and digital systems due to their ability to serve as long-term non-volatile memory. When used in programmable analog applications, the charge on the floating gates must be set very precisely, thereby necessitating precise and steady high voltages to generate programming conditions. In this work, we present a regulated charge pump with extremely low output ripple (<;1mV) that can be used for accurate programming of floating-gate transistors with channel hot-electron injection. To reduce the ripple to less than 1mV, we present a method to include a low drop-out regulator inside the charge-pump regulation loop. This 0.1196mm
²
charge pump was fabricated in a 0.35μm standard CMOS process. While operating from a 2.5V supply, this charge pump generates regulated voltages up to 10V.