A new method of frequency compensation for bipolar Wilson current mirror

Author

Filanovsky, I.M. ; Lee, Wilson H Y

Author_Institution

Dept. of Electr. & Comput. Eng., Alberta Univ., Edmonton, Alta., Canada

Volume

46

Issue

5

fYear

1999

fDate

5/1/1999 12:00:00 AM

Firstpage

500

Lastpage

506

Abstract

This paper proposes a new method of frequency compensation for a bipolar Wilson current mirror. The mirror is, first, modified: a resistor is inserted into the collector circuit of the diode-connected transistor, and another resistor of equal value is added into the emitter circuit of the same transistor. A compensation capacitor is connected between the collector and base of the feedback transistor. It is shown that the modification produces a pole-zero pair in the current-source transfer function. The split between pole and zero is reduced when the resistor value increases. This results in a wider bandwidth of the mirror transfer function and a faster step-transient response. These improvements are paid for in a small degradation of noise performance

Keywords

bipolar analogue integrated circuits; circuit feedback; compensation; current mirrors; equivalent circuits; integrated circuit noise; linear network analysis; poles and zeros; step response; transfer functions; transient response; bipolar Wilson current mirror; collector circuit; compensation capacitor; current-source transfer function; diode-connected transistor; emitter circuit; feedback transistor; frequency compensation; mirror transfer function; pole-zero pair; step-transient response; Bandwidth; Capacitors; Circuits; Diodes; Feedback; Frequency; Mirrors; Poles and zeros; Resistors; Transfer functions;

fLanguage

English

Journal_Title

Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1057-7130

Type

jour

DOI

10.1109/82.769798

Filename

769798