Micro Controller (¦Ìc) Reset Circuit Design

Microcontroller-reset circuit is a kind of integrated circuits, which is used widely. It has lot of advantages such as high integration, good cost-performance ratio, less external components and good performance. Almost all microcontrollers must have reset circuit. Using reset-circuits are very popular in the designs, in that they cannot only reduce the design complexity and the number of components, but improve system reliability and accuracy significantly, compared to separate ICs and discrete components. Modern reset-circuits have the characteristic of multifunction, which allows many functions besides voltage monitoring such as watch dog timing, data protection and battery switching. For all these advantages, reset-circuits have been applied in many fields, including computers, criticalμC power monitoring and intelligent instruments.The purpose of this paper is to design a kind of multifunctional, low-consumeμC reset-circuits chip. In this design, it's composed of the band gap, oscillator, voltage comparator and resistance networks modules etc. it affords many functions including power-down protection, power-on reset, manual-reset and primary-power detect etc. This paper has finished the circuit design, simulation and layout design. The simulation of the whole circuit shows that the design function and technical target is achieved. Improving the circuit, the author has designed aμC reset circuit whose static current is only 9uA with CMOS technology, then realize the low power requestment.In the design, we adopted the design methodology of"top to down": customize the design request-circuit design-simulation-layout design-drc/lvs verifying. The EDA tools used in the design includes Hspice,Virtuoso layout,Dracula of Cadence.The design was based on 0.5μm CMOS DPDM mixed signal technology of the CSMC Technologies Corporation. The simulation results obtained show that the functions and performances of this supervisory circuits chip meet the spec well. This paper has given practical design scheme, simulation results and layout.