Reconfigurable equalization architecture for high-speed receivers
First Claim
Patent Images
1. A programmable integrated circuit device comprising:
- a decision feedback equalizer configured to equalize an input signal, wherein the decision feedback equalizer comprises;
a summer circuit configured to sum the input signal with a plurality of signals, wherein the summer circuit includes a first transistor and second transistor arranged as a differential pair;
the first transistor configured to receive the input signal and the second transistor configured to receive a complement of the input signal;
a resistor disposed between the first transistor and the second transistor configured to provide resistor degeneration;
a first current source disposed at a first node connecting the first transistor and the resistor, the first current source configured to provide offset cancellation; and
a second current source disposed at a second node connecting the second transistor and the resistor, the second current source configured to provide offset cancellation; and
logic circuitry configured to control the first current source and the second current source based on stored calibration data.
1 Assignment
0 Petitions
Accused Products
Abstract
Systems and methods are disclosed for employing an equalization technique that improves equalizer input sensitivity and which reduces power consumption. In particular, an equalization architecture is described that includes a continuous-time linear equalizer and a decision feedback equalizer, each with offset cancellation that enables the equalizer to be used at high data rates. In addition, the equalization structure has a power-saving mode for bypassing the decision feedback equalizer. These offset cancellation and power-saving features are enabled and controlled using programmable logic on a programmable device.
37 Citations
20 Claims
-
1. A programmable integrated circuit device comprising:
-
a decision feedback equalizer configured to equalize an input signal, wherein the decision feedback equalizer comprises; a summer circuit configured to sum the input signal with a plurality of signals, wherein the summer circuit includes a first transistor and second transistor arranged as a differential pair; the first transistor configured to receive the input signal and the second transistor configured to receive a complement of the input signal; a resistor disposed between the first transistor and the second transistor configured to provide resistor degeneration; a first current source disposed at a first node connecting the first transistor and the resistor, the first current source configured to provide offset cancellation; and a second current source disposed at a second node connecting the second transistor and the resistor, the second current source configured to provide offset cancellation; and logic circuitry configured to control the first current source and the second current source based on stored calibration data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A programmable integrated circuit device comprising:
-
a continuous time linear equalizer configured to equalize an input signal; a decision feedback equalizer configured to receive the equalized input signal and to provide an output signal, wherein the decision feedback equalizer comprises a high path and a low path; and logic circuitry configured to; determine whether the decision feedback equalizer is in a bypass mode; and in response to determining that the decision feedback equalizer is in the bypass mode, (a) disable the low path and (b) provide, using the high path, the equalized input signal as the output signal. - View Dependent Claims (12)
-
-
13. A method for equalizing an input signal using a decision feedback equalizer, the method comprising:
-
receiving, with logic circuitry, an indication to use the decision feedback equalizer in one of a plurality of modes; and in response to the indication; providing an input signal to a first summer circuit in the decision feedback equalizer; disabling, with the logic circuitry, a second summer circuit coupled to the first summer circuit in the decision feedback equalizer; and configuring, with the logic circuitry, a multiplexer coupled to the first summer circuit and the second summer circuit to select a signal generated by the first summer circuit for output. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
-
Specification