Accuracy bootstrapping

Abstract

A method and apparatus for a system physically realizing a transfer function and having improved accuracy and fast calibration is described, comprising a plurality of stages configured in a serial fashion, each stage having a transfer function realized with fixed and adjustable elements. Control logic for selectively reconfiguring said stages, operable for coupling any one of said stages to a reference signal and for further coupling said one of said stages to the remaining ones of said stages in a serial fashion is added; control logic for selectively causing said stages to transmit at their output responses to an input which enable measurement of individual components within said stages is included; and control logic for updating the adjustable elements within each stage is described. A calibration technique is disclosed wherein the system is reconfigured to allow any one of said stages to be configured as the first stage in a chain made up of all of said stages, serially coupled, the first stage outputting signals indicative of the value of components within it in response to selective excitation by the reference signal, the remaining stages capturing said outputted signals and storing the result as a measurement. The calibration process continues until the adjustable elements within each stage have been updated. Additional cycles may be performed for increased accuracy. An additional preferred embodiment of an analog-to-digital converter implemented using the accuracy bootstrapping invention is disclosed. Other embodiments are also disclosed.