National Semiconductor Corporation

Lattice Semiconductor Corporation

Allan Lin

Vinh Ho

Jay Deng

Magathi Jayaram

L Vincent Xie

Carl Chai

A Class AB amplifier has a control stage and a push-pull stage. The control stage has a programmable resistor that allows a floating constant voltage to applied to the push-pull stage such that the quiescent current of the amplifier is relatively low. The configuration enables the amplifier to operate properly at relatively low power-supply voltage levels. The amplifier can be configured as the output driver for an operational amplifier (op-amp) with a Miller compensation configuration that replaces the conventional Miller compensation resistor with a transistor that is part of the op-amp.

Class AB amplifier with programmable quiescent current

In one embodiment, a hybrid output buffer having both an H-bridge mode and a CML mode of operation includes a plurality of transistor switches arranged between an upper rail and a bottom rail. A first pair of the transistor switches couples between the upper rail and respective output nodes. A pair of resistors couples between the output nodes and a central node. During H-bridge mode, the hybrid output buffer controls a potential of the upper rail responsive to a feedback signal proportional to a difference between a potential of the central node and a common-mode voltage.

Hybrid H-bridge and CML driver

A data source circuit and a complementary data recovery circuit which can transmit and receive data at a higher rate than a conventional data source circuit which uses similar fabrication technology. A data source circuit of the present invention has an input for receiving a periodic source clock signal having a period T; a synchronization signal generator for generating, based on said downstream-clock signal, a series of one or more periodic synchronization signals having periods substantially equal to T, each synchronization signal being delayed from a previous synchronization signal; and a transmitter for transmitting one or more sub-words of a multi-bit data word, each sub-word having one or more bits, separate ones of said one or more sub-words being transmitted responsive to separate progressively delayed combined pairs of said synchronization signals. In a preferred embodiment of the present invention particularly suited for use in a point to point (e.g. a ring-type) data network, a recovery circuit and a source circuit are integrated as a receiver/retransmission node.

Source synchronized data transmission circuit

A circuit is for re-synchronizing an event indication signal received from a foreign domain to generate a result indication signal that is re-synchronized to a host clock signal. The event indication signal is received from the foreign domain at a first input terminal; and a host clock signal is received at a second input terminal. Edge-triggered flip flop circuitry of the circuit has a clock input, a data input, and a data output. The clock input is coupled to the second input terminal and the data input is coupled to receive a latch output signal. The edge-triggered flip flop circuitry clocks the latch output signal to the data output of the flip flop circuitry, to generate a result event indication signal, in response to a transition in the host clock signal. Delay circuitry is coupled to the first input terminal to receive the event indication signal. The delay circuitry provides a delayed event indication signal having a phase that is delayed from the event indication signal. Transparent latch circuitry latches the delayed event indication signal responsive to a latch control signal, and combination circuitry is coupled to receive the event indication signal and the result event indication signal, and provides a combination thereof as the latch control signal.

Circuit for coupling an event indication signal across asynchronous time

A data source circuit and a complementary data acquisition circuit which can transmit and receive data at a higher rate than a conventional data source circuit which uses similar fabrication technology. A data source circuit of the present invention has an input for receiving a periodic source clock signal having a period T; a synchronization signal generator for generating, based on said downstream-clock signal, a series of one or more periodic synchronization signals having periods substantially equal to T, each synchronization signal being delayed from a previous synchronization signal; and a transmitter for transmitting one or more sub-words of a multi-bit data word, each sub-word having one or more bits, separate ones of said one or more sub-words being transmitted responsive to separate progressively delayed combined pairs of said synchronization signals. In a preferred embodiment of the present invention particularly suited for use in a point to point (e.g. a ring-type) data network, an acquisition circuit and a source circuit are integrated as a receiver/retransmission node.

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San Jose, CA, United States of America

Allan Lin