Low-voltage low-power reference circuits for an autonomous robot: I-SWARM

In this paper it is presented the design of the power supply system for an autonomous robot of few mm3 called I-SWARM (Intelligent Small World Autonomous Robots for Micro-manipulation) which is based on the design of a low-dropout regulator (LDO), and a bandgap reference circuit (BG), that has been designed for the LDO. The paper presents the design, stability issues and full Montecarlo studies about the performances of the BG circuit and the LDO regulator, for different temperature and supply conditions. The regulator has been developed to supply the required voltage for the electronics involved in the robot to be tested in a near future. The regulator is based on a low-dropout linear regulator (LDO). The architecture of the BG is based on a peaking current mirror circuit with MOSFET transistors, working in the sub-threshold region. This architecture is very interesting because it presents a good trade-off between performances, area and power dissipation. These circuits have been designed in a 0.13 &mgr;m technology from ST Microelectronics through the CMP-TIMA service.