Abstract: An interdigitated Metal-Insulator-Metal (MIM) capacitor provides self-shielding and accurate capacitance ratios with small capacitance values. The MIM capacitor includes two terminals that extend to a plurality of interdigitated fingers separated by an insulator. Metal plates occupy layers above and below the fingers and connect to fingers of one terminal. As a result, the MIM capacitor provides self-shielding to one terminal. Additional shielding may be employed by a series of additional shielding layers that are isolated from the capacitor. The self-shielding and additional shielding may also be implemented at an array of MIM capacitors.

Abstract: A charge transfer circuit, such as a charge coupled device or other bucket brigade device, which incorporates an amplifier to assist with charge transfer.

Abstract: A technique for increasing the charge storage capacity of a charge storage device without changing its inherent charge transfer function. The technique may be used to implement a charge domain signal processing circuits such as Analog to Digital Converters (ADCs) used in digital radio frequency signal receivers.

Abstract: An approach to rejecting input common-mode voltage variations in a sampler/converter that avoids the use of a differential amplifier in the signal path, and without introducing added distortion or noise. In one embodiment, the input common-mode variations are sensed on a pair of matched resistors that straddle the common mode analog inputs, on a node ‘Vcmi’. An alternative, switched-capacitor-based sensing scheme is also possible. Using this measured Vcmi, adjustments are then made to the rest of the sampler/converter to take out any variations observed at Vcmi.

Abstract: A technique for operating a source follower buffer circuit, such as employed in a charge domain pipeline, to eliminate floating diffusion signal charge contamination from downstream circuits. The method and apparatus places an output of the circuit in a known state immediately prior to charge transfer into a floating diffusion, and again in known state immediately prior to charge transfer out of the floating diffusion.

Abstract: An approach to rejecting input common-mode voltage variations in a sampler/converter that avoids the use of a differential amplifier in the signal path, and without introducing added distortion or noise. In one embodiment, the input common-mode variations are sensed on a pair of matched resistors that straddle the common mode analog inputs, on a node ‘Vcmi’. An alternative, switched-capacitor-based sensing scheme is also possible. Using this measured Vcmi, adjustments are then made to the rest of the sampler/converter to take out any variations observed at Vcmi.

Abstract: A technique for increasing the charge storage capacity of a charge storage device without changing its inherent charge transfer function. The technique may be used to implement a charge domain signal processing circuits such as Analog to Digital Converters (ADCs) used in digital radio frequency signal receivers.

Abstract: An adjustment circuit for use with a resistive reference ladder that establishes nominal reference steps and a common mode voltage for a plurality of comparators, such as used in a flash converter. An “H” arrangement of current sources injects current at a first node, VH, and sinks at a second node, VL. with VH, and VL. being coupled to ends of the ladder. The voltage difference between these two nodes thus controls the scale applied to the reference ladder, without affecting a common mode voltage reference Vcm. Alternatively, the current source may inject current at VL and sink current at VH to decrease the reference for each comparator.

Abstract: A technique for increasing the charge storage capacity of a charge storage device without changing its inherent charge transfer function. The technique may be used to implement a charge domain signal processing circuits such as Analog to Digital Converters (ADCs) used in digital radio frequency signal receivers.

Abstract: A low-power communication interface, such as used with 10 Gigabit Ethernet, that uses an analog front end having a charge-domain analog-to-digital converter that uses a charge-domain pipeline.

Abstract: A method and structure of providing a doped plug to improve the performance of CCD gaps is discussed. A highly-doped region is implemented in a semiconductor, aligned beneath a gap. The plug provides a highly-conductive region at the semiconductor surface, therefore preventing the development of a region where potential is significantly influenced by surface charges.

Abstract: An approach to rejecting input common-mode voltage variations in a sampler/converter that avoids the use of a differential amplifier in the signal path, and without introducing added distortion or noise. In one embodiment, the input common-mode variations are sensed on a pair of matched resistors that straddle the common mode analog inputs, on a node ‘Vcmi’. An alternative, switched-capacitor-based sensing scheme is also possible. Using this measured Vcmi, adjustments are then made to the rest of the sampler/converter to take out any variations observed at Vcmi.

Abstract: A differential reference ladder with an auto zero circuit that can be used as part of a flash analog to digital converter. The auto zero operation is performed relative to a common mode voltage of the ladder. The resistive ladder is disconnected from the rest of the circuit during auto zero mode. As a result, the auto zero adjustment is more accurate, since the offsets are stored under the same common mode connection as when the circuit is in a compare mode. This permits auto zeroing to proceed quickly unencumbered by the parasitic capacitance of the ladder or other components.

Abstract: A single-ended charge-domain pipeline of at least two stages is provided. Each stage comprises a charge-storage node, a charge-transfer circuit for conveying charge from said charge-storage node out of said stage, a charge-control capacitor connected to said charge-storage node and driven by a periodic clock voltage, a comparator which compares the voltage of said charge-storage node to a reference voltage, and a digital latch which latches the state of said comparator output under control of a second periodic clock voltage and provides a latched digital output from said stage. The second stage of the pipeline further includes a first charge-redistribution capacitor connected to the charge-storage node of the second stage and driven by a conditional voltage responsive to the latched digital output from the first stage. The charge output from each stage of said pipeline is substantially identical to the charge input to said stage.

Abstract: In a differential bucket-brigade device (BBD) pipeline it is necessary for proper circuit function to maintain the common-mode charge within an acceptable range at each pipeline stage. Embodiments of the present invention provide for reducing common-mode charge variations in a differential charge-domain pipeline. Common mode charge at a given stage of the pipeline is adjusted according to one or more measured characteristics, thereby controlling common mode charge variation throughout the differential charge-domain pipeline.

Abstract: A technique for operating a source follower buffer circuit, such as employed in a charge domain pipeline, to eliminate floating diffusion signal charge contamination from downstream circuits. The method and apparatus places an output of the circuit in a known state immediately prior to charge transfer into a floating diffusion, and again in known state immediately prior to charge transfer out of the floating diffusion.

Abstract: A differential reference ladder with an auto zero circuit that can be used as part of a flash analog to digital converter. The auto zero operation is performed relative to a common mode voltage of the ladder. The resistive ladder is disconnected from the rest of the circuit during auto zero mode. As a result, the auto zero adjustment is more accurate, since the offsets are stored under the same common mode connection as when the circuit is in a compare mode. This permits auto zeroing to proceed quickly unencumbered by the parasitic capacitance of the ladder or other components.

Abstract: A technique for increasing the charge storage capacity of a charge storage device without changing its inherent charge transfer function. The technique may be used to implement a charge domain signal processing circuits such as Analog to Digital Converters (ADCs) used in digital radio frequency signal receivers.

Abstract: A technique for correcting charge transfer inefficiencies in a Charge Coupled Device (CCD). The basic approach is to estimate the charge entering at a given stage in a CCD pipeline, and to then determine an estimate of the error introduced by the accumulated leftover charge that will be present at a second point, farther down the pipeline. The error is then corrected by injecting a correcting charge at a third point, farther still down the CCD pipeline. The invention is used, in one embodiment, to correct the output of a charge to digital converter, although principals of the invention may be used for other types of circuits.

Abstract: A Direct Current (DC) charge comparator that provides low input offset by feeding complimentary plus and minus charge inputs to a single amplification path via an alternate input path switch. Multiple sample and hold circuits at the output of the amplification path permit comparison of the result when each of the charge inputs travels down each of the paths, to determine a correction.