Abstract:
Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems. The C3MOS structure enables the use of a power supply voltage that may be larger than the voltage required by the CMOS fabrication process, further enhancing the performance of the circuit.
Abstract translation:用于实现超高速电路的各种电路技术使用以常规CMOS工艺技术制造的电流控制CMOS(C 3/4 MOS)逻辑。 包括逆变器/缓冲器,电平移位器,NAND,NOR,异或门,锁存器,触发器等的整个逻辑元件族都使用C 3 MOS技术实现。 通过将高速C“3”MOS逻辑与低功耗常规CMOS逻辑相结合,实现了每个电路应用的功耗和速度之间的最佳平衡。 组合的三极管/ CMOS逻辑允许诸如光纤通信系统中使用的高速收发器之类的电路的更大集成。 C 3 O 3 MOS结构能够使用可能大于CMOS制造工艺所需的电压的电源电压,进一步提高电路的性能。
Abstract:
The invention discloses a system for improving performance of the RF amplification stage of communication receivers by accounting for the signal environment of the RF amplifier. The linearity, gain and power supply voltage of the RF amplification stage of the communication receiver is adjusted to produce an optimal signal into the succeeding narrow-band amplification stage(s). The adjustment of the RF stage includes mechanisms such as adjusting the RF amplifier power supply level using a DC to DC converter. It also includes allowing distortion in the RF amplification stage if the distortion in the RF amplification stage does not affect the target signal. For example, if there were a strong signal that fell within the same band as the target signal, amplification would be allowed to be so high that it distorted the undesired signals, but not the tined signals. If the desired signal is the predominant signal, within the RF amplifier's band, then the amplifier gain may be increased only to the point where distortion is detected.
Abstract:
Techniques for generating bias voltages for a multi-cascode amplifier. In an aspect, a multi-cascode bias network is provided, each transistor in the bias network being a replica of a corresponding transistor in the multi-cascode amplifier, enabling accurate biasing of the transistors in the multi-cascode amplifier. In another aspect, a voltage supply for the multi-cascode amplifier is provided separately from a voltage supply for the replica bias network, to advantageously decouple variations in the amplifier voltage supply from the bias network voltage supply. In yet another aspect, the bias voltages of transistors in the multi-cascode amplifier may be configured by adjusting the impedance of resistive voltage dividers coupled to the transistor gate biases. As the gain of the amplifier depends on the bias voltages of the cascode amplifiers, the gain of the amplifier may be adjusted in this manner without introducing a variable gain element directly in the amplifier signal path.
Abstract:
Various example embodiments are disclosed. According to an example embodiment, an apparatus may include a continuous time filter, a decision feedback equalizer, a clock and data recovery circuit, and an adaptation circuit. The adaptation circuit may be configured to adapt equalization according to at least one dithering algorithm by adjusting a delay adjust signal based on a mean square error of equalized data signals.
Abstract:
Equalization is provided in a high speed communication receiver that includes in various aspects an automatic gain control input stage, a decision feedback equalizer, a clock and data recovery circuit and equalization control circuits. The automatic gain control stage may include a continuous time filter with an adjustable bandwidth. A threshold adjust signal may be applied to the output of the automatic gain control stage. The equalization control circuits may be implemented in the digital domain and operate at a lower clock speed than the data path.
Abstract:
The present invention provides a clock circuit to produce a Reference Clock Signal used to latch data between first bit stream(s) and second bit stream(s), wherein the number and bit rate of the first bit stream(s) and the second bit stream(s) differ. The VCO generates one of a number of inputs to a PLL within the clock circuit. At a minimum, these inputs include a first bit stream data clock. Additionally, these inputs may further include a Loop Timing Clock Signal, an External Reference Clock Signal, and/or a Reverse Clock Signal for the PLL. The input provided by the VCO make up a VCO Output Signal wherein a filtering circuit that circuit includes a capacitor and a resistor reduces noise contained within the VCO Output Signal.
Abstract:
A method and apparatus for adaptively controlling a variable gain amplifier (VGA). The operation of the VGA is separated into a low gain mode and a high gain mode and the mode in which the VGA is currently operating in is adaptively sensed. A threshold voltage is compared to a control voltage of the VGA; if the VGA is currently operating in the low gain mode and the control voltage is higher than the threshold voltage, the VGA is switched from the low gain mode to the high gain mode; and if the VGA is currently operating in the high gain mode and the control voltage is lower than the threshold voltage, the VGA is switched from the high gain mode to the low gain mode.
Abstract:
Equalization is provided in a high speed communication receiver that includes in various aspects an automatic gain control input stage, a decision feedback equalizer, a clock and data recovery circuit and equalization control circuits. The automatic gain control stage may include a continuous time filter with an adjustable bandwidth. A threshold adjust signal may be applied to the output of the automatic gain control stage. The equalization control circuits may be implemented in the digital domain and operate at a lower clock speed than the data path.
Abstract:
An integrated circuit includes a core circuit and a buffer circuit. The buffer circuit includes a plurality of input buffers and a plurality of output buffers that service a plurality of voltage domains on a single set of input/output lines. These voltage domains are controllable to service multiple voltage levels, consistent with various interface standards. In one construction, the core circuit operates at 1.2 volts and the buffer circuit supports both a 1.2 volts interface standard and a 3.3 volts interface standard.
Abstract:
A communication system for the wireless transmission of information through a single antenna is disclosed. The communication system comprises a handset and one or more modules capable of being coupled to the handset. The handset processes baseband information signals being received and transmitted, and transmits and receives radio frequency (RF) information signals through its antenna. Each module is removably couplable to the handset for converting baseband information signals into RF information signals for transmission, and for converting received RF information signals into baseband information signals. Each removably couplable module is optimized to enable wireless communication in accordance with at least one communication standard when coupled to the handset. By coupling the appropriate module with the handset, wireless communication in a number of geographic locations may be achieved.