Invention Grant
US07683815B2 Cross-coupled switched capacitor circuit with a plurality of branches
有权
具有多个分支的交叉耦合开关电容器电路
- Patent Title: Cross-coupled switched capacitor circuit with a plurality of branches
- Patent Title (中): 具有多个分支的交叉耦合开关电容器电路
-
Application No.: US12133458Application Date: 2008-06-05
-
Publication No.: US07683815B2Publication Date: 2010-03-23
- Inventor: Olafur Josefsson , Khiem Nguyen
- Applicant: Olafur Josefsson , Khiem Nguyen
- Applicant Address: US MA Norwood
- Assignee: Analog Devices, Inc.
- Current Assignee: Analog Devices, Inc.
- Current Assignee Address: US MA Norwood
- Agency: Sunstein Kahn Murphy & Timbers LLP
- Main IPC: H03M3/00
- IPC: H03M3/00

Abstract:
A cross-coupled switched capacitor circuit that has two branches. During a first phase for the first branch, an input voltage is provided that causes charge to move through a resistor and to be placed onto a plate of the capacitor within the branch. An equivalent amount of charge is transferred to an output node. The output node may be a summing node of a sigma-delta modulator. The summing node is one of the inputs to an operational amplifier that is part of the integrator of the sigma-delta modulator. The resistor and the capacitor in the first branch define an RC circuit and corresponding RC time constant. During the first phase, the capacitor does not reach a fully settled voltage for a desired resolution. During the second phase, the capacitor in the first branch of the circuit is set to a defined voltage. The defined voltage may be the settling voltage had the capacitor been allowed to settle during the first phase. The second branch of the switched capacitor feedback circuit operates similar to the first branch, but on opposite phases. By not requiring the voltage to settle during the first phase, power can be conserved, since the integrator of the sigma-delta modulator does not need to operate as fast with respect to movement of charge.
Public/Granted literature
- US20080303703A1 Cross-Coupled Switched Capacitor Circuit with a Plurality of Branches Public/Granted day:2008-12-11
Information query