The Research Of Incremental Sigma-Delta Modulator For Gas-Gauge Of Li Battery

With the increasingly popularity of electronic equipment in lithium battery, lithium battery applications are more widely. Thus the accurate detection of the lithium battery becomes more and more important, which requires a more accurate analog-to-digital converter. The traditional Sigma-Delta analog-to-digital converter is mainly used for the high-band signal detection. Lithium battery detection requires accurate detection of battery outflow DC signal transform. Traditional analog-to-digital converter is usually unable to meet this requirement, so Sigma-Delta ADC, a specialized for DC high-precision detection of the incremental type is widely used in this field.This article is mainly for Incremental Sigma-Delta ADC analog portion of the Sigma-Delta modulator design, at the same time to discuss the post-filter algorithm feasibility. Using a top-down design philosophy selected from the structure of the system, system modeling to the details of each module detailed design, and ultimately constitutes the entire modulator. Generally Incremental Sigma-Delta Modulator analog module design requirements are more lenient, so this discussion focused on system-level design.In response to the selection of the system configuration, the paper chooses the third order feed-forward single-bit quantization of the modulator structure.For the DC detector, single bit gets better linearity, and is more suited for such applications. On the other hand feed-forward structure is more suitable for incremental Sigma-Delta analog-to-digital converter requirements. System modeling uses the corresponding method versus the traditional Sigma-Delta analog-to-digital converter modeling for its own design. The core operational amplifier circuit used for the realization of the circuit is the main discussion, which is given the major indicators of theoretical formula derivation, and the simulation results.The entire system is in the TSMC0.35μm process simulation, and the simulation result is the14.56bit, to meet the design requirements of14bit.