Pipelined analog-to-digital converters with gain-matching structures

DETAILED DESCRIPTION The present invention is directed to pipelined ADC system embodiments which provide gain matching structures that substantially eliminate gain errors between preceding and succeeding converter stages.
The invention recognizes that gain across main signal-conditioning elements of pipelined ADC systems will vary with process and temperature variations and generate code errors in digital output signals S.
sub.
out.
In response to this recognition, the invention provides reference signal-conditioning elements that mimic at least one of the main signal-conditioning elements.
The reference signal-conditioning elements control a reference signal to a succeeding digital-to-analog converter (DAC) so that a match is maintained between the full-scale range of the succeeding DAC and the "gained-up" step size of a preceding DAC.
This match substantially eliminates the code errors.
The novel features of the invention are set forth with particularity in the appended claims.
The invention will be best understood from the following description when read in conjunction with the accompanying drawings.