Abstract: A divide-by-three circuit includes a chain of three dynamic flip-flops and a feedback circuit of combinatorial logic. The divide-by-three circuit receives a clock signal that synchronously clocks each dynamic flip-flop. The feedback circuit supplies a feedback signal onto the first dynamic-flop of the chain. In a first mode, a signal from a slave stage of the first flip-flop and a signal from a slave stage of the second flip-flop are used by the feedback circuit to generate the feedback signal. In a second mode, a signal from a master stage of the first flip-flop and a signal from a master stage of the second flip-flop are used by the feedback circuit to generate the feedback signal. By proper selection of the mode, the frequency range of the overall divider is extended. Combinatorial logic converts thirty-three percent duty cycle signals from the flip-flop chain into fifty percent duty cycle quadrature signals.

Abstract: Techniques for designing a switchable amplifier are described. In one aspect, a switchable amplifier including a core amplifier circuit configured to selectively enable one or more parallel input transistor pairs is described. The core amplifier circuit comprises a permanently enabled input transistor pair. In another aspect, a device operable between a first mode of operation and a second mode of operation comprising a receiver logic circuit for selectably enabling and disabling a plurality of input transistor pairs within a switchable amplifier is described where the switchable amplifier also includes a core amplifier circuit coupled to the receiver logic circuit for selectably enabling and disabling a transistor pair therein. The described switchable amplifiers result in the ability to provide varying amplifier performance characteristics based upon the current mode of operation of the device.

Abstract: A device with multiple multi-mode low-noise amplifiers (LNAs), each with common operating modes and separate operating frequency bands, are coupled to shared degenerative inductors for common operating modes. Common load inductors are coupled to the multi-mode LNA outputs to reduce the number of load inductors required. The multi-mode LNAs have parallel transistor gain stages and form part of an integrated circuit (IC) for use in a wireless communication receiver. Each multi-mode LNA has the capability to switch between at least one higher linearity transistor gain stage and at least one lower linearity transistor gain stage for different operating modes. Multiple lower linearity transistor gain stages for different multi-mode LNAs may be merged into a single lower linearity transistor gain stage shared among multiple multi-mode LNAs through multiple RF switches between a set of common RF inputs and common inputs and common input matching networks.

Abstract: A divide-by-three circuit includes a chain of three dynamic flip-flops and a feedback circuit of combinatorial logic. The divide-by-three circuit receives a clock signal that synchronously clocks each dynamic flip-flop. The feedback circuit supplies a feedback signal onto the first dynamic-flop of the chain. In a first mode, a signal from a slave stage of the first flip-flop and a signal from a slave stage of the second flip-flop are used by the feedback circuit to generate the feedback signal. In a second mode, a signal from a master stage of the first flip-flop and a signal from a master stage of the second flip-flop are used by the feedback circuit to generate the feedback signal. By proper selection of the mode, the frequency range of the overall divider is extended. Combinatorial logic converts thirty-three percent duty cycle signals from the flip-flop chain into fifty percent duty cycle quadrature signals.

Abstract: A device with multiple multi-mode low-noise amplifiers (LNAs), each with common operating modes and separate operating frequency bands, are coupled to shared degenerative inductors for common operating modes. Common load inductors are coupled to the multi-mode LNA outputs to reduce the number of load inductors required. The multi-mode LNAs have parallel transistor gain stages and form part of an integrated circuit (IC) for use in a wireless communication receiver. Each multi-mode LNA has the capability to switch between at least one higher linearity transistor gain stage and at least one lower linearity transistor gain stage for different operating modes. Multiple lower linearity transistor gain stages for different multi-mode LNAs may be merged into a single lower linearity transistor gain stage shared among multiple multi-mode LNAs through multiple RF switches between a set of common RF inputs and common inputs and common input matching networks.

Abstract: Techniques for designing a switchable amplifier are described. In one aspect, a switchable amplifier including a core amplifier circuit configured to selectively enable one or more parallel input transistor pairs is described. The core amplifier circuit comprises a permanently enabled input transistor pair. In another aspect, a device operable between a first mode of operation and a second mode of operation comprising a receiver logic circuit for selectably enabling and disabling a plurality of input transistor pairs within a switchable amplifier is described where the switchable amplifier also includes a core amplifier circuit coupled to the receiver logic circuit for selectably enabling and disabling a transistor pair therein. The described switchable amplifiers result in the ability to provide varying amplifier performance characteristics based upon the current mode of operation of the device.