C8051F98x Microcontrollers Silicon Labs C8051F98x Capacitive Sensing MCUs further expand the low-power C8051F9xx product family. The C8051F98x series is designed to address smaller memory, lower power, and more cost-sensitive microcontroller applications. Silicon Labs C8051F98x Capacitive Sensing MCUs are available in 2, 4, and 8kB flash sizes. These microcontrollers are the most cost-effective option in the C8051F9xx ultra-low power series.