Adaptive current sense amplifier with direct array access capability
First Claim
1. A current sense amplifier circuit, comprising:
- a reference current leg that includes a reference limit section coupled between a first data node and a bias current node;
a data current leg that includes a data limit section coupled between a second data node and a sense current node; and
an equalization circuit that includesa first equalization path coupled between the first data node the second data node, and a second equalization path coupled between the bias current node and the sense current node, the first and second equalization paths providing a high or low impedance in response to an equalization signal, anda first limit section coupled between a first power supply node and the bias current node, and a second limit section coupled between the first power supply node and the data current node;
whereina current flowing through the reference limit section, data limit section, first limit section and second limit section is limited according to a limit voltage.
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Accused Products
Abstract
A current sense amplifier can include an active load circuit having a first load device and second load device coupled in parallel to a first power supply node. A first load device and second load device can provide an impedance that varies according to a potential at a load control node. A reference current circuit can be coupled between the first load device and a second power supply node that includes a current reference section that provides an impedance according to a bias voltage. A data current circuit can be coupled between the second load device and a plurality of memory cells. An adaptive bias circuit can be coupled between the first power supply and the second power supply node and can include a bias section coupled to the load control node that provides an impedance according to the bias voltage.
79 Citations
20 Claims
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1. A current sense amplifier circuit, comprising:
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a reference current leg that includes a reference limit section coupled between a first data node and a bias current node; a data current leg that includes a data limit section coupled between a second data node and a sense current node; and an equalization circuit that includes a first equalization path coupled between the first data node the second data node, and a second equalization path coupled between the bias current node and the sense current node, the first and second equalization paths providing a high or low impedance in response to an equalization signal, and a first limit section coupled between a first power supply node and the bias current node, and a second limit section coupled between the first power supply node and the data current node;
whereina current flowing through the reference limit section, data limit section, first limit section and second limit section is limited according to a limit voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A current sense amplifier, comprising:
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an active load circuit that includes a first load device and second load device coupled in parallel to a first power supply node, the first load device and second load device providing an impedance that varies according to a potential at a load control node; a reference current circuit coupled between the first load device and a second power supply node that includes a current reference section that provides an impedance according to a bias voltage; a data current circuit coupled between the second load device and a plurality of memory cells; and an adaptive bias circuit coupled between the first power supply and the second power supply node that includes a bias section coupled to the load control node that provides an impedance according to the bias voltage. - View Dependent Claims (13, 17)
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14. The current sense amplifier of 12, further including:
a reference digital to analog converter having an input coupled to receive a reference digital value and an output coupled to provide the reference voltage.
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15. The current sense amplifier of 12, further including:
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the reference current circuit further includes a reference limit section coupled to a first data node that provides an impedance that varies according to a limit voltage; the data current circuit includes a data limit section coupled to a second data node that provides an impedance that varies according to the limit voltage; and a precharge circuit that includes a first precharge section coupled between the first power supply node and the first data node that provides an impedance according to the limit voltage, and a second precharge section coupled between the first power supply node and the second data node that provides an impedance according to the limit voltage. - View Dependent Claims (16)
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18. A method of sensing a data value by comparing a sensed current to a reference current, comprising the steps of:
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in a sense mode, limiting a voltage on the data current node to no more than a maximum voltage limit based on a limit voltage, limiting a current flow through a reference current leg and a data current leg to no more than a maximum current limit based on a limit voltage, controlling the current flowing through the reference current leg to value less than the maximum current limit according to a reference voltage, and varying an impedance of a load circuit coupled to the reference current leg and data current leg according to variations in the current flowing through the reference current leg; and in a precharge mode, precharging the reference current leg and the data current leg to a potential less than a high power supply level in response to the limit voltage. - View Dependent Claims (19, 20)
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Specification