INTEGRATED CIRCUITS AND METHODS FOR ENABLING HIGH-SPEED AC-COUPLED NETWORKS TO SUPPRESS NOISE DURING LOW-FREQUENCY OPERATION
First Claim
1. An alternating-current (AC) coupling integrated circuit (IC) for suppressing signal errors introduced by a steady-state input, the AC-coupling IC comprising:
- an operational amplifier having an inverting signal input, a non-inverting signal input, and an output;
a true direct-current (DC) bias network having a first branch and a second branch, the first branch and the second branch of the true DC-bias network coupled to each other and to the non-inverting signal input;
a complimentary DC-bias network having a third branch and a fourth branch, the third branch and the fourth branch of the complimentary DC-bias network coupled to each other and to the inverting signal input;
a first feedback element coupled to the output of the operational amplifier and arranged to generate a first control signal in response to a characteristic of the input signal; and
a second feedback element coupled to the output of the operational amplifier and arranged to generate a second control signal in response to a characteristic of the input signal.
2 Assignments
0 Petitions
Accused Products
Abstract
An alternating-current (AC) coupling integrated circuit (IC) suppresses signal errors introduced by a steady-state input signal. The IC includes an operational amplifier, a true direct-current (DC) bias network, a complimentary DC-bias network and first and second feedback elements. The operational amplifier has an inverting input, a non-inverting input and an output. The true DC-bias network has first and second branches that are coupled to one another and the non-inverting input. The complimentary DC-bias network has third and fourth branches that are coupled to one another and the inverting input. First and second feedback elements generate first and second control signals in response to a characteristic of one of the true input signal and the complimentary input signal. The control signals prevent the voltage at the inputs to the operational amplifier from reaching an equivalent, steady-state, DC-bias voltage.
9 Citations
20 Claims
-
1. An alternating-current (AC) coupling integrated circuit (IC) for suppressing signal errors introduced by a steady-state input, the AC-coupling IC comprising:
-
an operational amplifier having an inverting signal input, a non-inverting signal input, and an output; a true direct-current (DC) bias network having a first branch and a second branch, the first branch and the second branch of the true DC-bias network coupled to each other and to the non-inverting signal input; a complimentary DC-bias network having a third branch and a fourth branch, the third branch and the fourth branch of the complimentary DC-bias network coupled to each other and to the inverting signal input; a first feedback element coupled to the output of the operational amplifier and arranged to generate a first control signal in response to a characteristic of the input signal; and a second feedback element coupled to the output of the operational amplifier and arranged to generate a second control signal in response to a characteristic of the input signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A method for enabling high-speed AC-coupled networks to suppress noise during low-frequency operation, the method comprising:
-
coupling a true DC-bias network having a first branch and a second branch to the non-inverting signal input of an operational amplifier; coupling a complimentary DC-bias network having a third branch and a fourth branch to the inverting input of an operational amplifier; using a first feedback element coupled between an output of the operational amplifier and one of the true DC-bias network and the complimentary DC-bias network to generate a first control signal in response to a characteristic of a true input signal applied to one of the true DC-bias network and a complimentary input signal applied to the complimentary DC-bias network; controllably applying the first control signal to at least one of the first branch of the true DC-bias network and the third branch of the complimentary DC-bias network; using a second feedback element coupled between the output of the operational amplifier and one of the true DC-bias network and the complimentary DC-bias network to generate a second control signal in response to the characteristic of the true input signal applied to one of the true DC-bias network and the complimentary input signal applied to the complimentary DC-bias network; and controllably applying the second control signal to at least one of the second branch of the true DC-bias network and the fourth branch of the complimentary DC-bias network. - View Dependent Claims (19, 20)
-
Specification