Time-division data multiplexer with feedback for clock cross-over adjustment
First Claim
1. A time-division multiplexer with an adjustable clock cross-over voltage, comprising:
- a multi-phase clock generator comprising a plurality of select clock outputs with different phases;
a plurality of data inputs;
first and second data outputs;
a first set of gating transistors which is coupled between the first data output and a common node, with each transistor in the first set being gated by a corresponding data input and at least one corresponding select clock output;
a second set of gating transistors which is coupled between the second data output and the common node, with each transistor in the second set being gated by a corresponding data input and at least one corresponding select clock output;
a first current source coupled to the common node;
a reference voltage generator; and
an amplifier comprising a first input coupled to the common node, a second input coupled to the reference voltage generator and a cross-over control output coupled to the plurality of select clock outputs for adjusting cross-over of the select clock outputs.
7 Assignments
0 Petitions
Accused Products
Abstract
A time-division data multiplexer has feedback for adjusting the select clock cross-over voltage. The multiplexer includes a multi-phase clock generator having a plurality of select clock outputs with different phases, a plurality of parallel data inputs and first and second serial data outputs. A first set of gating transistors is coupled between the first data output and a common node. Each transistor in the first set is gated by a corresponding data input and at least one corresponding select clock output. A second set of gating transistors is coupled between the second data output and the common node. Each transistor in the second set is gated by a corresponding data input and at least one corresponding select clock output. A first current source is coupled to the common node. An amplifier has a first input which is coupled to the common node, a second input which is coupled to a reference voltage generator and a cross-over control output which is coupled to the plurality of select clock outputs for adjusting the cross-over voltage of the select clock outputs in response to a comparison of the voltages on the first and second amplifier inputs. A loop filter is coupled to the cross-over control output.
-
Citations
20 Claims
-
1. A time-division multiplexer with an adjustable clock cross-over voltage, comprising:
-
a multi-phase clock generator comprising a plurality of select clock outputs with different phases; a plurality of data inputs; first and second data outputs; a first set of gating transistors which is coupled between the first data output and a common node, with each transistor in the first set being gated by a corresponding data input and at least one corresponding select clock output; a second set of gating transistors which is coupled between the second data output and the common node, with each transistor in the second set being gated by a corresponding data input and at least one corresponding select clock output; a first current source coupled to the common node; a reference voltage generator; and an amplifier comprising a first input coupled to the common node, a second input coupled to the reference voltage generator and a cross-over control output coupled to the plurality of select clock outputs for adjusting cross-over of the select clock outputs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. An n:
- 1 time-division multiplexer, where n is an even integer, the multiplexer comprising;
clock generator means for generating n/2 pairs of select clock signals, wherein the select clock signals in each pair are approximately 180 degrees out of phase with one another and have an adjustable cross-over voltage, and wherein the n select clock signals are equally distributed in phase over 360 degrees; a set of n true and complement data inputs;
first and second data outputs;a first set of n gating transistors coupled between the first data output and a common node, with each transistor in the first set being gated by a corresponding true data input and corresponding select clock signals; a second set of n gating transistors coupled between the second data output and the common node, with each transistor in the second set being gated by a corresponding complement data input and the corresponding select clock signals; first current source means for supplying a tail current to the common node; reference means for generating a reference voltage on a reference node which is representative of a voltage on the common node when only one of the transistors in the n pairs of data gating transistors is enabled at one time; means for comparing the voltages on the reference node and the common node and for generating a cross-over control output which is representative of the comparison; and means for adjusting the cross-over voltage of the select clock outputs as a function of the cross-over control output.
- 1 time-division multiplexer, where n is an even integer, the multiplexer comprising;
-
17. A time-division multiplexer comprising:
- first and second supply terminals;
a multi-phase clock generator comprising a plurality of select clock outputs with different phases; a set of true and complement data inputs; first and second data outputs; a first set of gating transistors coupled between the first data output and a common node, with each transistor in the first set being gated by a corresponding true data input and at least one corresponding select clock output; a second set of gating transistors coupled between the second data output and the common node, with each transistor in the second set being gated by a corresponding complement data input and at least one corresponding select clock output; reference means for generating a reference voltage which is representative of an average of the voltages on the first and second data outputs when only one of the transistors in the first and second sets is enabled; means for comparing the average of the voltages on the first and second data outputs with the reference voltage and for generating a cross-over control output which is representative of the comparison; and means for adjusting the cross-over voltage of the select clock outputs as a function of the cross-over control output. - View Dependent Claims (18, 19)
- first and second supply terminals;
-
20. A method of serializing a plurality of parallel data inputs to a pair of data outputs, comprising:
-
generating at least one pair of select clock signals which are approximately 180 degrees out of phase with one another; selectively coupling the data outputs to a common node as a function of the plurality of data inputs and the select clock signals; comparing the voltage on the common node with a reference voltage; and adjusting cross-over of the select clock signals as a function of the comparison.
-
Specification