Sensing circuits and methods of operating nonvolatile memory devices based on operating temperatures

A nonvolatile memory device comprising:

• a memory cell array including a plurality of memory cells coupled to a plurality of word-lines and a plurality of bit-lines;
• a column selection circuit including a plurality of selection transistors coupled to the bit-lines, respectively;
• a sensing circuit connected to the column selection circuit;
• and
• a control circuit configured to control the column selection circuit and the sensing circuit based on a command and an address,
• wherein the sensing circuit includes:
• a precharge current generator connected to a sensing node and configured to generate a precharge current provided to a first bit-line of the plurality of bit-lines, in response to a precharge signal;
• an adjusting transistor connected between the sensing node and a first node coupled to the first bit-line, the adjusting transistor configured to adjust an amount of the precharge current provided to the first bit-line in response to a first control voltage;
• and
• an adaptive control voltage generator configured to generate a control current which is proportional to an operating temperature of the nonvolatile memory device, in response to the precharge signal and a second control voltage and configured to boost a level of the first control voltage in proportion to the operating temperature, based on the control current, wherein the second control voltage is inversely proportional to the operating temperature.

A method of operating a nonvolatile memory device, wherein the nonvolatile memory device includes a memory cell array including a plurality of memory cells coupled to a plurality of word-lines and a plurality of bit-lines, a column selection circuit including a plurality of selection transistors coupled to the bit-lines, respectively, and a sensing circuit connected to the column selection circuit, the method comprising:

• providing, by the sensing circuit, a precharge current to a sensing node;
• adjusting the precharge current provided to a selected bit-line among the bit-lines according to an operating temperature of the nonvolatile memory device by applying a first control voltage to a gate of an adjusting transistor that connects the sensing node to a first group of selection transistors among the selection transistors, a level of the first control voltage increasing in proportional to the operating temperature;
• applying a boost voltage greater than a power supply voltage to a first selection transistor and a first word-line, wherein the first selection transistor of the first group of selection transistors is coupled to the selected bit-line and the first word-line is coupled to a selected memory cell;
• and
• sensing a voltage of the sensing node to output data.