摘要:
Apparatuses and methods are provided relating to a voltage controlled oscillator (VCO) based on current starved inverting delay stages; wherein in each stage a PMOS transistor as header and an NMOS transistor as footer are used with their gate-to-source voltages always equal to analog control voltage. The analog control voltage is also used as the supply voltage of the oscillator. An exemplary apparatus includes a VCO of n stages, where n is an odd number and where each stage includes a current starved inverter where the analog control voltage is also used as the supply voltage of each delay stage.
摘要:
A method for implementing phase rotator circuits and phase rotator circuit of the invention includes a polyphase filter network to create a quadrature phase version of the input signal. The polyphase filter network is partitioned into a first part that is physically isolated from the phase rotator circuit and a second part that is embedded in the phase rotator circuit. The second part of the polyphase filter is coupled to the first part of the polyphase filter by a high-pass equalizing buffer stage. The second part of the polyphase filter is coupled to the phase rotator circuit by a bandlimiting buffer stage.
摘要:
A decision feedback equalizer (DFE) and method include summer circuits configured to add a dynamic feedback tap to a received input to provide a sum and to add a speculative static tap to the sum. Sense amplifiers are configured to receive outputs of the summer circuits and evaluate the outputs of the summer circuits in accordance with a clock signal. A passgate multiplexer is configured to receive outputs from sense amplifiers wherein the multiplexers is clock-gated for isolation of subsequent ciruitry from the outputs of the sense amplifiers during a precharged period. A gating circuit is configured to perform gating of a selected signal output from a second circuit portion with a clock signal and to enable the isolation of the subsequent circuitry by the multiplexer during the precharge period. A regenerative buffer is coupled to the multiplexer to maintain an output of the multiplexer during the precharge period, to provide the select signal for a passgate multiplexer in the second circuit portion of the DFE and to drive the dynamic feedback tap on the first circuit portion of the DFE.
摘要:
Methods and apparatus are disclosed for calibrating summing amplifiers based on current integration. For example, apparatus for calibrating output voltage levels of a current-integrating summing amplifier includes the following components. A duplicate integrator circuit is provided, wherein the duplicate integrator circuit replicates an integrator circuit of the current-integrating summing amplifier. A comparing circuit, coupled to the duplicate integrator circuit, is provided for comparing at least one output voltage level generated by the duplicate integrator circuit with a reference voltage level. A feedback loop circuit, coupled to the comparing circuit and the duplicate integrator circuit, is provided for adjusting at least one bias signal of the duplicate integrator circuit so that the output voltage level generated by the duplicate integrator circuit matches the reference voltage level, wherein the bias signal is applied to the integrator circuit of the current-integrating summing amplifier thereby calibrating output signal components due to multiple input signals of the current-integrating summing amplifier.
摘要:
A method for implementing phase rotator circuits and phase rotator circuit of the invention includes a polyphase filter network to create a quadrature phase version of the input signal. The polyphase filter network is partitioned into a first part that is physically isolated from the phase rotator circuit and a second part that is embedded in the phase rotator circuit. The second part of the polyphase filter is coupled to the first part of the polyphase filter by a high-pass equalizing buffer stage. The second part of the polyphase filter is coupled to the phase rotator circuit by a bandlimiting buffer stage.
摘要:
Methods and apparatus are disclosed for calibrating summing amplifiers based on current integration. For example, apparatus for calibrating output voltage levels of a current-integrating summing amplifier includes the following components. A duplicate integrator circuit is provided, wherein the duplicate integrator circuit replicates an integrator circuit of the current-integrating summing amplifier. A comparing circuit, coupled to the duplicate integrator circuit, is provided for comparing at least one output voltage level generated by the duplicate integrator circuit with a reference voltage level. A feedback loop circuit, coupled to the comparing circuit and the duplicate integrator circuit, is provided for adjusting at least one bias signal of the duplicate integrator circuit so that the output voltage level generated by the duplicate integrator circuit matches the reference voltage level, wherein the bias signal is applied to the integrator circuit of the current-integrating summing amplifier thereby calibrating output signal components due to multiple input signals of the current-integrating summing amplifier.
摘要:
A decision feedback equalizer (DFE) and method include summer circuits configured to add a dynamic feedback tap to a received input to provide a sum and to add a speculative static tap to the sum. Sense amplifiers are configured to receive outputs of the summer circuits and evaluate the outputs of the summer circuits in accordance with a clock signal. A passgate multiplexer is configured to receive outputs from sense amplifiers wherein the multiplexer is clock-gated for isolation of subsequent circuitry from the outputs of the sense amplifiers during a precharge period. A gating circuit is configured to perform gating of a select signal output from a second circuit portion with a clock signal and to enable the isolation of the subsequent circuitry by the multiplexer during the precharge period. A regenerative buffer is coupled to the multiplexer to maintain an output of the multiplexer during the precharge period, to provide the select signal for a passgate multiplexer in the second circuit portion of the DFE and to drive the dynamic feedback tap on the first circuit portion of the DFE.