Analysis and Design Procedure of LVLP Sub-bandgap Reference - Development and Results

Abstract

This work presents an thorough analysis and design of a low-voltage low-power voltage reference circuit with sub-bandgap output voltage. The outcome of the analysis and the resulting design rules are universal and it is supposed to be general and suitable for similar topologies with just minor modifications. The general analysis is followed by a selection of specific topology. The given topology is analyzed for particular parameters which are standard industrial circuit specifications. These parameters are mathematically expressed, some are simplified and equivalent circuits are used. The analysis and proposed design procedure focuses mainly on versatility of the IP block. The features of the circuit suit to low-voltage low-power design with less than 10μA supply current draw at 1.3V supply voltage. For testing purposes a complex transistor level design was created and verified in wide range of supply voltages (1.3 to 3.3V) and temperatures (-45 to 95°C) all in concrete 0.35μm IC design process using Mentor Graphics® and Cadence® software.