Abstract:
Techniques for accommodating an incoming signal at a front-end receiver via AC-coupling or DC-coupling are described herein. In one aspect, a front-end receiver comprises a differential input with a first data line and a second data line for receiving an incoming signal. The front-end receiver also comprises an AC-coupled switch coupled to the differential input, wherein the AC-coupled switch is configured to both perform high-pass filtering on the incoming signal and offset the filtered incoming signal with a DC-offset voltage if an AC-coupling mode of the receiver is enabled. The front-end receiver further comprises a DC-coupled switch coupled to the differential input, wherein the DC-coupled switch is configured to shift a common-mode voltage of the incoming signal if a DC-coupling mode of the receiver is enabled.
Abstract:
Certain aspects of the present disclosure provide techniques and apparatus for glitch-free bandwidth switching in a phase-locked loop (PLL). One example PLL generally includes a voltage-controlled oscillator (VCO) comprising a first variable capacitive element and a second variable capacitive element and a bandwidth adjustment circuit comprising a first switch in parallel with a resistor of a resistor-capacitor (RC) network. The bandwidth adjustment circuit is configured to open the first switch for a first bandwidth mode, close the first switch in a transition from the first bandwidth mode to a second bandwidth mode, and control a capacitance of the second variable capacitive element based on a voltage of a node of the RC network.
Abstract:
A clock distribution architecture is provided in which the output clock signals from a plurality of fractional-N PLLs have a known phase relationship because each fractional-N PLL is configured to commence a phase accumulation responsive to a corresponding edge of a reference clock signal.
Abstract:
An integrated circuit (IC) is disclosed for time-to-digital conversion with a latch-based ring. In example aspects, the IC includes a ring, a counter, an encoder, and time-to-digital converter (TDC) control circuitry. The ring includes multiple ring stages and propagates a ring signal between successive ring stages. Each respective ring stage includes latch circuitry to secure a state of the ring signal at the respective ring stage. The ring provides a ring output signal using the latch circuitry of each of the ring stages. The ring is coupled to the counter. The counter increments a counter value responsive to the ring signal and provides a counter output signal based on the counter value. The encoder is coupled to the ring and the counter. The encoder generates a TDC output signal based on the ring and counter output signals. The TDC control circuitry operates the ring responsive to a TDC input signal.
Abstract:
A series of current repeaters with localized feedback is provided. Each current that precedes a subsequent current repeater in the series is configured to receive a feedback current from the subsequent current repeater and generate an error signal accordingly with a differential amplifier so as to reduce current repetition errors that would otherwise result from an offset voltage in the differential amplifier.
Abstract:
Methods and systems according to one or more embodiments are provided for frequency detection. In an embodiment, a frequency detector is provided that includes a capacitor that discharges or charges responsive to binary states of an input signal.
Abstract:
A master-slave level shifter array includes an asymmetric master level shifter having a predefined output state that produces an enable signal to drive an array of symmetric slave level shifters during a power collapse. As a result, the slave level shifter array has a reliable output state during a power collapse, while also providing wafer area savings due to their small symmetric characteristics.
Abstract:
A phase locked loop has a frequency divider included in a feedback path. The frequency divider generates a first output and a delayed output. The phase locked loop also includes a charge pump to generate an output current based on the first output and the delayed output of the frequency divider.
Abstract:
A phase continuity architecture is provided to maintain the phase continuity for a post divider output signal from a post divider that post divides a PLL output signal. A pulse swallower removes a pulse from the PLL output signal responsive to an edge is a divided feedback clock signal. A sampler samples the post divider output signal responsive to a detection of the missing pulse to determine a phase relationship between the post divider output signal and the divided feedback clock signal.
Abstract:
A phase discontinuity mitigation implementation within a phased lock loop (PLL) improves throughput of a radio access technology. The throughput is improved by maintaining a phase of the PLL while powering off some devices of the PLL, such as a local oscillator (LO) frequency divider. In one instance, when the PLL is powered down, one or more portions of a delta sigma modulator for the PLL are clocked with a reference clock for the PLL. This implementation maintains phase continuity when the first phase lock loop turns back on.