Switched-Opamp Technique for Low-Voltage Switched Capacitor Circuits
A new switched-opamp technique is proposed to operate switched-capacitor circuits at supply voltages as low as 1-V without on-chip voltage multiplier or low-Vt devices. The main idea of the new switched-opamp technique is to implement an additional switchable operational amplifier (opamp) in parallel but in an alternate clock phase compared to the original switched opamp. As such, for every clock phase, there exists an opamp that is fully functional in the switched-capacitor system. The two switchable opamps are further combined to realize a single two-switchable-output-pair opamp to save power and area and to minimize the mismatch. Unlike existing ones, the proposed switched-opamp technique can be directly applied to implement most of the existing classical switched-capacitor circuits and is highly compatible with their synthesizing techniques. By using the new technique, switched-capacitor circuits can be designed to operate at high frequencies with only a single 1-V supply in a standard CMOS process.
In the proposed switched-opamp technique, the opamps allow multi-phase operation, making it fully functional at any time, and consequently can be combined with other switched-capacitor techniques to achieve higher performance in terms of speed, supply voltage, and power consumption. As such, it can be applied to implement high-performance switched-capacitor filters and analog-to-digital converters for wireless and telecommunication applications.
- All existing switched-capacitor circuits, in particular filters and analog-to-digital converters
- Low-voltage high-frequency applications, including wireless and telecommunications
Patent Number: US6344767B1
Application Number: US2000493264A
Inventor: Cheung, Sin Luen | Luong, Howard Cam
Priority Date: 28 Jan 2000
Priority Number: US6344767B1
Application Date: 28 Jan 2000
Publication Date: 5 Feb 2002
IPC Current: G11C002702 | H03F000300 | H03F000330 | H03F000345 | H03F000372
US Class: 327336 | 327337 | 327345
Assignee Applicant: The Hong Kong University of Science & Technology
Title: Switched-opamp technique for low-voltage switched capacitor circuits
Usefulness: Switched-opamp technique for low-voltage switched capacitor circuits
Summary: For low voltage switched-capacitor system. Also used for pseudo-n-path double sampling, capacitance spread reduction and sample correction techniques implemented in standard CMOS technology.
Novelty: Switched operational amplifier circuit for low voltage switched capacitor system, consists of two operational amplifiers which are connected in parallel and are operated in alternate clock phases
電子
半導體
28 Jan 2000
US 6344767
TTC.PA.115
香港
