Abstract:
Circuit techniques are disclosed for improving the SFDR of a DAC. In an embodiment, a DAC includes a resistor ladder network operably coupled to input logic circuitry and an output. The input logic circuitry receives a multi-bit input signal and effectively creates a plurality of processed input signals therefrom. The resistor ladder network is configured to receive the plurality of processed input signals and includes a corresponding plurality of current paths. Each current path includes: a current switch operably controlled by one of the processed input signals; a first resistor in series with the current switch; a second resistor in series with the first resistor; and a feedforward capacitor in parallel with the second resistor. The output is operably coupled to each of the plurality of current paths and is configured to output an analog output signal that corresponds to the multi-bit input signal.
Abstract:
A zero knowledge communications protocol is provided that can unconditionally secure communications sent through a communications network by encrypting all messages, continuously sending noise messages through the network, and routing all network activity through an anonymity network. This combination of components prevent an eavesdropper on the network from garnering any information about when a communication is sent, the contents and statistics of a communication, the sender, or the intended recipient of the communication.
Abstract:
Frequency divider techniques are disclosed which can be used to address two problems: when an incorrect division occurs if the modulus control changes before the divide cycle is complete, and when an incorrect division occurs due to a boundary crossing (e.g., power-of-2 boundary crossing in a fractional-N PLL application). In one embodiment, a frequency divider is provided comprising a plurality of flip-flops operatively coupled to carry out division of an input frequency, and configured to generate a modulus output and receive a divided clock signal of a previous cell. An additional flip-flop is selectively clocked off one of the modulus output or the divided clock of the previous stage, depending at least in part on a Skip control signal applied to a data input of the additional flip-flop, and is further configured to selectively reset the plurality of flip-flops to a state that will result in a correct divide ratio.