A low-noise bandgap voltage reference employing dynamic element matching

Bandgap voltages references are widely used in IC design, but are sensitive to low-frequency noise and component mismatch. This thesis describes the design and testing of a new IC voltage reference that targets these issues through three dynamic element matching (DEM) subsystems. The first is a chopper OTA, and the second two are component rotation schemes: one to exchange the positions of two critical resistors, and the second to cycle through all BJTs, periodically selecting each to participate as the "1" transistor of the N:1 bandgap ratio. Practical designs that address the various switching issues typically associated with DEM, such as glitch and clock drift, are described. Analytic expressions for the effects of noise and mismatch throughout the bandgap reference are derived, along with expressions for calculating the improvement that can be achieved by DEM. A test chip was implemented in a 0.25[mu]m BiCMOS process; with its three DEM subsystems enabled it is shown to achieve a 20x 1/f noise improvement and a 34x mismatch error improvement.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2011

Author dc:creator

• Herbst, Steven (Steven G.)

Advisor dc:contributor.advisor

• Charlie Sodini.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/77071

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/77071