Configurable and Intelligent Switched CMOS Current Driver Powering Arrays of Electrothermal Actuators for MEMS Switches

A switched constant current driver for a configurable switch network based on electrothermal micro-electromechanical-systems (MEMS) components is presented. A constant current-mode approach is proposed for achieving precise power control over an array of devices that leverage thermal heaters for actuation. This multi-channel actuation circuit is able to power different electrothermal MEMS switches. Interface circuits based on the self-temperature sensing technique of the heater and the ohmic contact property of the actuator are proposed. They provide early detection to address MEMS lifetime concerns, and constitute the main novelty of this research, which is specifically focused on the application. The circuit is implemented in a 0.18 μm BCD technology and occupies an area of 1.3 mm
²
. Post-layout simulations show that the system can output current up to 90 mA (R
heater
= 80 Ω) with a resolution of 2 mA.