Abstract: A circuit includes a first die having a first array of exposed data nodes, and a second die having a second array of exposed data nodes, wherein a given data node of the first array corresponds to a respective data node on the second array, further wherein the first array and the second array share a spatial arrangement of the data nodes, wherein the first die has data inputs and sequential logic circuits for each of the data nodes of the first array on a first side of the first array, and wherein the second die has data outputs and sequential logic circuits for each of the data nodes of the second array on a second side of the second array, the first and second sides being different.

Abstract: Circuits for die-to-die clock distribution are provided. A system includes a transmit clock tree on a first die and a receive clock tree on a second die. The transmit clock tree and the receive clock tree are the same, or very nearly the same, so that the insertion delay for a given bit on the transmit clock tree is the same as an insertion delay for a bit corresponding to the given bit on the receive clock tree. While there may be clock skew from bit-to-bit within the same clock tree, corresponding bits on the different die experience the same clock insertion delays.

Abstract: Circuits and methods for Data Bus Inversion (DBI) are provided. In one example, the immediately previous value of the DBI bit affects the next value of the DBI bit. Specifically, in some instances, the value of the DBI bit is held to the immediately previous value of the DBI bit to limit the total number of transitions on a data bus.

Abstract: A control circuit generates data signals and configuration commands that are provided to an interface circuit. The interface circuit includes a configuration circuit that generates configuration signals according to the configuration commands and a drive component that generates interface signals according to the data signals. The interface signals are generated with a drive characteristic determined according to the configuration signals applied to configuration devices that selectively activate a configuration of drive devices. A diagnostic circuit is coupled to the control circuit and the interface circuit and is configured to receive a test state indication and acquire a corresponding portion of the configuration signals. The diagnostic circuit compares the test state indication and the portion of the configuration signals to diagnose a stuck-at fault condition within a faulty configuration circuit and propagate a fault indication to the control circuit.

Abstract: A receiver is disclosed. The receiver includes an amplifier and a bias circuit configured to provide a bias current to the amplifier. The bias circuit is self biasing. The bias circuit is also configured to adjust the bias current using positive feedback from the amplifier.

Abstract: A receiver is disclosed. The receiver includes an amplifier and a bias circuit configured to provide a bias current to the amplifier. The bias circuit is self biasing. The bias circuit is also configured to adjust the bias current using positive feedback from the amplifier.

Abstract: A two-bit serializer circuit as described herein includes programmable delay elements having adjustable phase delay that allows for phase tuning of two parallel input signals relative to an output multiplexer select signal. The two parallel input signals are retimed relative to a reference clock signal, and one of the retimed signals is processed by a fixed delay element. This delayed intermediate signal is further delayed using one programmable delay element; the other retimed signal is delayed using another programmable delay element. The delayed output signals generated by the programmable delay elements are utilized as input signals to a high speed output multiplexer. The multiplexer output select signal represents a buffered version of the reference clock signal. The programmable nature of the serializer circuit facilitates tuning to reduce jitter in the serialized output signal.

Abstract: A ring oscillator stage includes two differential transistor pairs configured to add an adjustable amount of delay to a differential input signal. Each differential pair is biased with a bias current transistor; the bias current transistor is “protected” by a voltage-clamping transistor that limits the drain voltage of the bias current transistor. The voltage-clamping transistors enable use of a power supply voltage (VDD) that would otherwise exceed the reliability breakdown voltage limit of the bias current transistors.

Abstract: A voltage-controlled oscillator (“VCO”) structure includes a plurality of VCO circuits, each having a different nominal operating frequency range. Power consumption of the VCO structure is regulated by selective activation/deactivation of the individual VCO circuits. In a preferred embodiment, only one of the VCO circuits is active at any given time. The active VCO can be selected to satisfy the requirements of the particular application and/or to compensate for semiconductor manufacturing process variations.

Abstract: A clock generator circuit includes a plurality of phase delay elements connected in series. The phase delay elements provide delayed output clock signals relative to an input clock signal. The circuit employs a loop-back path that connects the output of the final phase delay element to the input of the first phase delay element. The loop-back path enables the circuit to maintain an accurate overall phase delay between the input clock signal and the output clock signal generated by the final phase delay element. When implemented to support differential clock signals, the inverted outputs of the phase delay elements also serve as delayed clock signals. In accordance with one practical embodiment, the clock phase generator circuit provides evenly distributed clock phases over one clock period.

Abstract: An amplitude of a differential output signal at a differential multiplexer is maximized by presenting, in response to a differential selection signal, a high impedance to each output port of each differential transistor of a non-selected differential transistor pair. A differential input signal is received at each differential transistor pair. Each transistor of each differential transistor pair is connected to a current source through an independent selection transistor. In response to the differential selection signal, each of the selection transistors is placed in an off state resulting in a high impedance between the output ports of the transistors of the non-selected differential transistor pair.

Abstract: An impedance element connecting the outputs of two transistors of a wide-bandwidth amplifier forms a zero. The output of transistor is connected to a current source. The wide-bandwidth amplifier has a bandwidth greater than conventional amplifiers utilizing a single current source without an increase in power dissipation.

Abstract: A programmable phase locked-loop (PLL) active filter circuit is provided which includes networks of cooperating bandwidth tuning components to select bandwidth ranges. The values and arrangement of the network of selectable series input (R1) resistors are chosen to be useful in both low band and high band settings. Likewise, the opamp network of feedback resistors (R2) and capacitors (C1) values are chosen to be useful in both low band and high band applications, automatically pairing with the R1 selection in response to a bandwidth range selection. These tuning components, internal to an integrated circuit, can be used for a plurality of wideband loops. External components can be used to supplement the internal components for low and high bandwidth applications.

Abstract: A source follower circuit for low voltage differential signaling (LVDS) has a low power consumption, low noise, and the ability to drive a highly capacitive load at an output port of an integrated circuit (IC). The source follower circuit includes a first p-channel transistor having a drain coupled to a supply voltage and a gate coupled to a first input; a second p-channel transistor having a drain coupled to the supply voltage and a gate coupled to a second input which is complementary to the first input; a third p-channel transistor having a gate coupled to the second input, a source coupled to ground, and a drain coupled to a source of the first p-channel transistor which forms a first output; and a fourth p-channel transistor having a source coupled to the ground and a drain coupled to a source of the second p-channel transistor which forms a second output which is complementary to the first output.

Abstract: A CMOS buffer for interfacing TTL-standard signals and capable of driving a high capacitance load such as a transmission line with low switching noise and low power consumption. The CMOS buffer includes two CMOS branch circuits that control the operation of a CMOS output device. Each branch circuit includes a first delay and a second delay greater than the first delay. The CMOS output device includes a complementary pair of MOS transistors. The first MOS transistor of the CMOS output device is operated by the first branch circuit in response to a signal that is delayed by the first or the second delay. The second MOS transistor of the CMOS output device is operated by the second branch circuit in response to delay of the signal by the second or the first delay.

Abstract: A complementary metal-oxide semiconductor (CMOS) integrated circuit that includes a clock recovery circuit. The clock recovery circuit automatically properly aligns a clock with data. A latch is used to perform the function of a flip-flop. Because the flip flop is essentially two latches, using the latch rather than the flip flop results in a circuit having one less latch. Consequently, the circuit has less propagation delay, which permits higher frequency operation. Use of the latch also reduces the load on the clock and saves power. Additionally, the clock recovery circuit uses differential logic, which decreases noise sensitivity and allows higher frequency operation.

Abstract: An integrated circuit complementary metal-oxide silicon (CMOS) voltage controlled oscillator (VCO) includes a plurality of variable delay elements, connected in a ring configuration, each variable delay element including a pair of parallel connected differential CMOS sections. The parallel-connected differential CMOS sections of each variable delay element are controlled by a differential control voltage whose magnitude sets relative levels of operation of the two differential sections of each variable delay element. These relative levels of operation determine the delay through the variable delay element. A current mirror circuit provides the differential control voltage.

Abstract: An integrated circuit complementary metal-oxide silicon (CMOS) voltage controlled oscillator (VCO) includes a plurality of variable delay elements, connected in a ring configuration, each variable delay element including a pair of parallel connected differential CMOS sections. The parallel-connected differential CMOS sections of each variable delay element are controlled by a differential control voltage whose magnitude sets relative levels of operation of the two differential sections of each variable delay element. These relative levels of operation determine the delay through the variable delay element. The control circuit provides the differential control voltage. The control circuit includes a first section for generating a control current and a pair of current mirror sections that divide the control current, generating a pair of differential control signal components as VGS potentials of a pair of CMOS transistors configured as current mirrors.

Abstract: A differential cMOS push-pull buffer includes a pair of push-pull sections, a cMOS current source transistor connected to the push-pull sections for providing current thereto, and two cMOS trickle current transistors, each connected to an output node of a respective push-pull section for conducting a trickle current at the output node. In each push-pull section a trickle current enhances the speed of operation, thereby maintaining desirable attributes in output waveforms.