Current sense amplifiers, memory devices and methods

A memory device, comprising:

• an array of memory cells;
• a read data path coupled to a set of data bus terminals;
• and
• a plurality of current sense amplifiers coupled to respective sets of memory cells in the array, each of the plurality of current sense amplifiers being configured to couple read data to one of the data bus terminals in the set responsive to sensing current from a respective one of the memory cells, each of the current sense amplifiers comprising:
• first and second current sense transistors, a drain of one of the first and second current sense transistors being coupled to the read data path, and a source of one of the first and second current sense transistors being coupled to the array, and the first current sense transistor including a gate coupled to the drain of the second current sense transistor and the second current sense transistor including a gate coupled to the drain of the first current sense transistor;
• a first clamping circuit coupled between drains of the first and second current sense transistors, the clamping circuit being configured to couple the drains of the first and second current sense transistors to each other responsive to a first clamp signal;
• a second clamping circuit coupled between the drains of the first and second current sense transistors, the second clamping circuit configured to couple the drains of the first and second current sense transistors to each other responsive to a second clamp signal;
• and
• a control circuit coupled to the clamping circuit, the control circuit configured to generate both the first clamp signal and the second clamp signal and apply the first clamp signal to the first clamping circuit and apply the second clamp signal to the second clamp signal to the second clamping circuit to actuate the first and second clamping circuits during at least some of the time that the current sense amplifier is sensing current coupled to the current sense amplifier from one of the memory cells in the array or coupled from the current sense amplifier to one of the memory cells in the array and to deactivate the first and second clamping circuits before the current sense amplifier has completed sensing current coupled to the current sense amplifier from one of the memory cells in the array or coupled from the current sense amplifier to one of the memory cells in the array.

A method of operating a current sense amplifier having first and second current sense transistors, each transistor including a source, a gate, and a drain, and the gates of the first current sense transistor coupled to the drain of the second current sense transistors and the gate of the second current sense transistor coupled to the drain of the first current sense transistor, the method comprising:

• coupling drains of the first and second current sense transistors to each other and terminating the coupling of the drains of the first and second current sense transistors to each other before the current sense amplifier has completed sensing current coupled to or from the source of one of the first and second current sense transistors, wherein coupling the drains of the first and second current sense transistors to each other comprises:
• coupling the drains of the first and second current sense transistors to each other through first and second coupling paths that are different from each other during at least some of the time that the current sense amplifier is sensing current coupled to or from the source of one of the first and second current sense transistors;
• terminating the coupling of the drains of the first and second current sense transistors to each other through the first coupling path at a first time before the current sense amplifier has completed sensing current coupled to or from the source of one of the first and second current sense transistors;
• and
• terminating the coupling of the drains of the first and second current sense transistors to each other through the second coupling path at a second time before the current sense amplifier has completed sensing current coupled to or from the source of one of the first and second current sense transistors, the second time being different from the first time.