The LM4132 family of precision voltage references performs comparable to the best laser-trimmed bipolar references, but in cost-effective CMOS technology. The key to this breakthrough is the use of EEPROM registers for correction of curvature, temperature coefficient (tempco), and accuracy on a CMOS band-gap architecture allowing package-level programming to overcome assembly shift. The shifts in voltage accuracy and tempco during assembly of die into plastic packages limit the accuracy of references trimmed with laser techniques.