Abstract: A phase locked loop (PLL) includes a first loop, a second loop, and a lock detector. The first loop locks a feedback signal having a frequency equal to a fraction of a frequency of an output signal to a reference signal in phase. The first loop has a first bandwidth. The second loop locks the feedback signal to the reference signal in frequency and has a second bandwidth. The first bandwidth is higher than the second bandwidth. The lock detector is coupled to the second loop and increases the second bandwidth in response to detecting that the feedback signal is not locked to the reference signal.

Abstract: A phase locked loop (PLL) includes a first loop, a second loop, and a lock detector. The first loop locks a feedback signal having a frequency equal to a fraction of a frequency of an output signal to a reference signal in phase. The first loop has a first bandwidth. The second loop locks the feedback signal to the reference signal in frequency and has a second bandwidth. The first bandwidth is higher than the second bandwidth. The lock detector is coupled to the second loop and increases the second bandwidth in response to detecting that the feedback signal is not locked to the reference signal.

Abstract: An amplifier circuit includes a first stage and a second stage. The first stage includes a differential input circuit coupled to a differential input node. The first stage includes a first partial cascode circuit including devices of a first type, the first partial cascode circuit being coupled to a first power supply node, a first bias node, and the differential input stage. The first stage includes a second partial cascode circuit including devices of a second type, the second partial cascode circuit being coupled to a second power supply node and the differential input circuit. The second stage is coupled to the first stage. The second stage includes a first full cascode circuit coupled to an output node.

Abstract: An integrated circuit includes a feedback controlled clock generating circuit, such as a DLL, PLL or other suitable circuit, that is operative to provide a feedback reference frequency signal based on a generated output clock signal. The integrated circuit also includes a programmable fine lock/unlock detection circuit that includes programmable static phase error sensitivity logic that senses phase error. The programmable static phase error sensitivity logic sets a phase lock sensitivity window used to determine a fine lock/unlock condition of the generated output clock signal. The programmable fine lock/unlock detection logic is also operative to generate a fine phase lock/unlock signal based on the set phase lock sensitivity window. The integrated circuit may also include a coarse lock detection circuit that generates a coarse lock signal based on a frequency unlock condition.

Abstract: An integrated circuit includes a feedback controlled clock generating circuit, such as a DLL, PLL or other suitable circuit, that is operative to provide a feedback reference frequency signal based on a generated output clock signal. The integrated circuit also includes a programmable fine lock/unlock detection circuit that includes programmable static phase error sensitivity logic that senses phase error. The programmable static phase error sensitivity logic sets a phase lock sensitivity window used to determine a fine lock/unlock condition of the generated output clock signal. The programmable fine lock/unlock detection logic is also operative to generate a fine phase lock/unlock signal based on the set phase lock sensitivity window. The integrated circuit may also include a coarse lock detection circuit that generates a coarse lock signal based on a frequency unlock condition.

Abstract: An amplifier circuit includes a first stage and a second stage. The first stage includes a differential input circuit coupled to a differential input node. The first stage includes a first partial cascode circuit including devices of a first type, the first partial cascode circuit being coupled to a first power supply node, a first bias node, and the differential input stage. The first stage includes a second partial cascode circuit including devices of a second type, the second partial cascode circuit being coupled to a second power supply node and the differential input circuit. The second stage is coupled to the first stage. The second stage includes a first full cascode circuit coupled to an output node.

Abstract: The invention provides a high-speed buffer that may used at the input of an integrated circuit, such as an input buffer. This buffer may be configured for use as a standard buffer with a single switching threshold, such as a TTL-to-CMOS buffer, or used as a Schmitt trigger with hysteresis, which as at least two switching thresholds. The integrated circuit may be a programmable logic device (PLD) or field programmable gate array (FPGA), but in other embodiments, the integrated circuit may be other types of devices such a microprocessors, ASICs, or memories.