Low-latency small-swing clocked receiver
AssigneeRambus Inc.
InventorJared L. Zerbe
Life of this patent
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Abstract
The present invention achieves the stated input receiver goals by merging many of the different functions required into a single unit instead of serializing them in the more traditional fashion. The present invention provides a receiver circuit having both a source-follower pair of MOS transistors, and a source-coupled pair of MOS transistors. The connecting node between these two pairs is coupled to a sense amplifier. The simultaneous use of the source-follower pair, the source-coupled pair and the sense-amplifier transistors allows for fast amplification of the low-swing input to full-rail CMOS, when triggered by a CMOS input clock.
Claims37
A receiver circuit comprising:
- a pair of nodes;
- a source follower pair of MOS transistors having a pair of sources coupled respectively to said pair of nodes, and a pair of gates coupled respectively to a pair of differential inputs;
- a source coupled pair of MOS transistors having a pair of drains coupled respectively to said pair of nodes, and a pair of gates coupled respectively to the pair of differential inputs;
- and
- a sense amplifier to convert signals at said pair of nodes from small swing signals into CMOS-level signals in response to and within a period of a clock signal.
A receiver circuit comprising:
- a pair of nodes;
- a source follower pair of MOS transistors having a pair of sources coupled respectively to said pair of nodes, and a pair of gates coupled respectively to a pair of differential inputs;
- a source coupled pair of MOS transistors having a pair of drains coupled to said pair of nodes, and a pair of gates coupled respectively to the pair of differential inputs;
- a sense amplifier coupled to said nodes;
- first and second pre-discharge transistors coupled to said nodes, and having gates coupled to a clock input;
- a first power savings transistor connected between a first one of said source coupled transistors and a first one of said nodes, said first power savings transistor having a gate coupled to a second one of said nodes;
- a second power savings transistor connected between a second one of said source coupled transistors and a second one of said nodes, said second power savings transistor having a gate connected to said first one of said nodes;
- first and second inverters having inputs connected to respective ones of said nodes, and outputs connected as outputs of said receiver circuit;
- and
- a power down transistor connected between a power supply and the drains of said source follower pair of MOS transistors, said power down transistor having a gate coupled to a power down line.
A receiver circuit comprising:
- first and second transistors having respective gate terminals and source terminals, the gate terminals being coupled to receive respective first and second input signals, respectively;
- third and fourth transistors having respective gate terminals and drain terminals, the gate terminals being coupled to receive the first and second input signals, respectively, and the drain terminals being coupled respectively to the source terminals of the first and second transistors;
- and
- a sense amplifier coupled to the source terminals of the first and second transistors, the sense amplifier being configured to amplify respective signals on the source terminals from small-swing signals to CMOS-level signals in response to, and within a single cycle of, a clock signal.
A receiver circuit comprising:
- a first MOS transistor having a first gate, a first source and a first drain, the first gate being coupled to a first input signal of a pair of low-swing, differential signals, the first source being coupled to a first node;
- a second MOS transistor having a second gate, a second source and a second drain, the second gate being coupled to a second input signal of the pair of low-swing, differential signals, the second source being coupled to a second node;
- a third MOS transistor having a third gate, a third source and a third drain, the third gate being coupled to the first input signal, the third drain being coupled to the second node;
- a fourth MOS transistor having a fourth gate, a fourth source and a fourth drain, the fourth gate being coupled to the second input signal, the fourth drain being coupled to the first node;
- and
- a sense amplifier having a first, second and third port, the first port being coupled to the first node, the second port being coupled to the second node, and the third port being coupled to a clock signal having a clock period, within a single clock period the sense amplifier converting the first and the second input signals into a first CMOS output signal coupled to the first node and a second CMOS output signal coupled to the second node.
A receiver circuit comprising:
- a first MOS transistor having a first gate, a first source and a first drain, the first gate being coupled to a first input signal of a pair of low-swing, differential signals, the first source being coupled to a first node;
- a second MOS transistor having a second gate, a second source and a second drain, the second gate being coupled to a second input signal of the pair of low-swing, differential signals, the second source being coupled to a second node;
- a third MOS transistor having a third gate, a third source and a third drain, the third gate being coupled to the first input signal, the third drain being coupled to the second node;
- a fourth MOS transistor having a fourth gate, a fourth source and a fourth drain, the fourth gate being coupled to the second input signal, the fourth drain being coupled to the first node;
- a sense amplifier having a first, second and third port, the first port being coupled to the first node, the second port being coupled to the second node, and the third port being coupled to a clock signal having a clock period, within a single clock period the sense amplifier converting the first and the second input signals into a first CMOS output signal coupled to the first node and a second CMOS output signal coupled to the second node;
- a first pre-discharge transistor having a fifth gate, a fifth source and a fifth drain, the fifth drain being coupled to the first node, the fifth gate being coupled to the clock signal;
- a second pre-discharge transistor having a sixth gate, a sixth source and a sixth drain, the sixth drain being coupled to the second node, and the sixth gate being coupled to the clock signal;
- a first power savings transistor having a seventh gate, a seventh source and a seventh drain, the seventh drain being connected to the second node, the seventh gate being coupled to the first drain, and the seventh source being connected to the third drain;
- a second power savings transistor having an eighth gate, an eighth source and an eighth drain, the eighth drain being coupled to the first node, the eighth gate being coupled to the second node, and the eighth source being connected to the fourth drain;
- a first inverter having a first inverter input coupled to the first node and a first inverter output coupled to a first output node of the receiver circuit, the first output node providing the first CMOS output signal;
- a second inverter having a second inverter input coupled to the second node a second inverter output coupled to a second output node of the receiver circuit, the second output node providing the second CMOS output signal;
- and
- a power down transistor having a ninth gate, a ninth source and a ninth drain, the ninth drain being coupled to a power down signal, the ninth drain being coupled to a power supply and the ninth source being connected to the first drain and the second drain.
Dependencies are inferred from the claim text.