A PWM analog memory programming circuit for floating-gate MOSFETs with 75-mu s programming time and 11-bit updating resolution

This paper describes a programming circuit for analog memory using pulsewid th modulation (PWM) signals and the circuit performance obtained from measu rements using a floating-gate EEPROM device. This programming circuit attai ns both high programming speed and high precision. We fabricated the progra mming circuit using standard 0.6-mum CMOS technology and constructed an ana log memory using the programming circuit and a floating-gate MOSFET. The me asurement results indicate that the analog memory attains a programming tim e of 75 mus, an updating resolution of 11 bite and a memory setting precisi on of 6.5 bit. This programming circuit can be used for intelligent informa tion processing hardware such as self-learning VLSI neural networks as well as multilevel flash memory.