Title
Compensation Method for Multi Stage Opamps with High Capacitive Load Using Negative Capacitance
Abstract
It is shown that negative capacitance (NC) circuits can be systematically used to improve the gain-bandwidth product (GBW) of the opamps. The NC circuit moves non-dominant pole of the opamp to higher frequency by decreasing the parasitic capacitance of the critical node. The impedance at the input of the NC circuits is neither purely capacitive nor negative at all frequencies. A design guide is presented by deriving the circuit model for a conventional NC circuit and investigating the extent of the improvement that can be achieved in a circuit by the use of the NC circuit. The model is then used to present the design guide for wide-banding the multistage opamps with large capacitive loads. Based on the proposed method a three-stage opamp with 15 nF capacitive load was designed and fabricated in a 0.18 m CMOS process. The measurements confirm that the opamp satisfies the design target of 1.5 MHz bandwidth (BW) at the power consumption of 75 W.
Year
DOI
Venue
2016
10.1109/TCSII.2016.2538138
IEEE Transactions Circuits and Systems II: Express Briefs
Keywords
DocType
Volume
Negative capacitance circuit,large capacitive load,low-power,opamp,wide-band
Journal
PP
Issue
ISSN
Citations 
99
1549-7747
1
PageRank 
References 
Authors
0.40
0
2
Name
Order
Citations
PageRank
Amirhossein Rasekh110.73
M. Sharif Bakhtiar251.51