Analog N-tap FIR receiver equalizer
First Claim
Patent Images
1. A receiver equalizer, comprising:
- samplers for sampling an incoming input data stream according to plural phases of a sampling clock, each sampler producing a demultiplexed data sample that changes at a slower rate than the incoming signal; and
a plurality of multi-tap finite impulse response (FIR) filters, where each FIR filter, in an analog domain, for each demultiplexed data sample, weights said demultiplexed data sample and at least one previous demultiplexed data sample, and combines said weighted data samples to produce an equalized demultiplexed data value, wherein each FIR filter includes at least one scaler, wherein each of the scalers has dedicated tap weight.
3 Assignments
0 Petitions
Accused Products
Abstract
An equalizer includes plural samplers for sampling an incoming input data stream according to plural phases of a sampling clock, each sampler producing a data sample. Operating in the analog domain, a multi-tap finite impulse response (FIR) filter weights the data samples and combines the weighted data samples to produce a filtered data bit. The filtered data bits thus form an equalized output data stream. The equalizer can compensate for characteristics of a communications channel, such as low-pass characteristics. The channel may carry high-speed, e.g., multi-gigabit per second, traffic.
21 Citations
21 Claims
-
1. A receiver equalizer, comprising:
-
samplers for sampling an incoming input data stream according to plural phases of a sampling clock, each sampler producing a demultiplexed data sample that changes at a slower rate than the incoming signal; and a plurality of multi-tap finite impulse response (FIR) filters, where each FIR filter, in an analog domain, for each demultiplexed data sample, weights said demultiplexed data sample and at least one previous demultiplexed data sample, and combines said weighted data samples to produce an equalized demultiplexed data value, wherein each FIR filter includes at least one scaler, wherein each of the scalers has dedicated tap weight. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for equalizing an incoming input data stream, comprising:
-
sampling the input data stream according to plural phases of a sampling clock to produce demultiplexed data samples changing at a slower rate than the incoming signal; and filtering the slow changing demultiplexed data samples with a plurality of analog multi-tap finite impulse response (FIR) filters, having dedicated tap weights, to produce demultiplexed equalized data values. - View Dependent Claims (12, 13, 14)
-
-
15. A receiver equalizer, comprising:
-
means for sampling the input data stream according to plural phases of a sampling clock to produce demultiplexed data samples changing at a lower rate than the incoming signal; and means for filtering the slower rate demultiplexed data samples with a plurality of an analog multi-tap finite impulse response (FIR) filters to produce demultiplexed equalized data values; means for sampling and holding the demultiplexed equalized data bit values; and means for converting the sampled equalized data bit values to digital values.
-
-
16. A multi-tap analog finite impulse response filter, comprising:
-
at least one combined voltage-current converter and scaler that produces a first current from an input voltage which is proportional to a product of a previous data sample voltage and a weight associated with said previous data sample tap; a voltage-current converter that produces a second current which is proportional to an instance data sample voltage; an adder circuit which subtracts the second current from the first current to produce a third current; and a converter circuit which converts the third current to a voltage corresponding to the equalized data voltage. - View Dependent Claims (17, 18)
-
-
19. A multi-tap analog finite impulse response filter method, comprising:
-
producing at least a first current from an input voltage which is proportional to a product of a previous data sample voltage and a weight associated with said previous data sample tap; producing a second current which is proportional to an instance data sample voltage; subtracting the second current from the first current to produce a third current; and converting the third current to a voltage corresponding to the filtered data bit. - View Dependent Claims (20)
-
-
21. A multi-tap analog finite impulse response filter, comprising:
-
means for producing at least a first current from an input voltage which is proportional to a product of a previous data sample voltage and a weight associated with said previous data sample tap; means for producing a second current which is proportional to an instance data sample voltage; means for subtracting the second current from the first current to produce a third current; and means for converting the third current to a voltage corresponding to the filtered data bit.
-
Specification