A device includes a comparator to provide an indication of a difference between Vp on a first terminal coupled to a top plate of each of a first group of differential capacitors, and Vn on a second terminal coupled to a top plate of each of a second group of differential capacitors. The device includes a control circuit coupled to the comparator. The control circuit is to receive a first indication of a difference between Vp and Vn; responsive to the first indication, cause a first driver to provide a reference voltage to bottom plates of one of the first and second groups, and cause a second driver to provide a ground voltage to bottom plates of the other of the first and second groups; receive a second indication of a difference between Vp and Vn; and provide a digital value responsive to the first indication and the second indication.

A device includes a comparator to provide an indication of a difference between Vp on a first terminal coupled to a top plate of each of a first group of differential capacitors, and Vn on a second terminal coupled to a top plate of each of a second group of differential capacitors. The device includes a control circuit coupled to the comparator. The control circuit is to receive a first indication of a difference between Vp and Vn; responsive to the first indication, cause a first driver to provide a reference voltage to bottom plates of one of the first and second groups, and cause a second driver to provide a ground voltage to bottom plates of the other of the first and second groups; receive a second indication of a difference between Vp and Vn; and provide a digital value responsive to the first indication and the second indication.

An internal voltage generation circuit includes an enable control circuit configured to generate a final enable signal by limiting an activation time point of an enable signal to a point in time after a reset time, after the enable signal is inactivated. The internal voltage generation circuit also includes a start-up control circuit configured to perform a reset operation during the reset time and generate a start-up signal based on the final enable signal, a reference voltage generation circuit configured to generate a reference voltage based on the start-up signal, a current generation circuit configured to generate a reference current based on the reference voltage, and a voltage generation circuit configured to generate an internal voltage based on the reference current.

An internal voltage generation circuit includes an enable control circuit configured to generate a final enable signal by limiting an activation time point of an enable signal to a point in time after a reset time, after the enable signal is inactivated. The internal voltage generation circuit also includes a start-up control circuit configured to perform a reset operation during the reset time and generate a start-up signal based on the final enable signal, a reference voltage generation circuit configured to generate a reference voltage based on the start-up signal, a current generation circuit configured to generate a reference current based on the reference voltage, and a voltage generation circuit configured to generate an internal voltage based on the reference current.

A storage circuit includes a memory cell array of memory cells each including a variable resistance type element, a resistance-voltage conversion circuit RT.sub.j to convert a resistance value of a memory cell MC.sub.ij to be read to a data voltage, a reference circuit and RT.sub.R to generate a reference voltage, a sense amplifier to determine read data by receiving the data voltage and the reference voltage via first and second input terminals, respectively, and comparing both voltages with each other, and an analog buffer circuit arranged between the resistance-voltage conversion circuit RT.sub.j and a first input terminal of the sense amplifier or between the reference circuit and RT.sub.R and a second input terminal of the sense amplifier. Current driving capability of the analog buffer circuit is large.

A storage circuit includes a memory cell array of memory cells each including a variable resistance type element, a resistance-voltage conversion circuit RT.sub.j to convert a resistance value of a memory cell MC.sub.ij to be read to a data voltage, a reference circuit and RT.sub.R to generate a reference voltage, a sense amplifier to determine read data by receiving the data voltage and the reference voltage via first and second input terminals, respectively, and comparing both voltages with each other, and an analog buffer circuit arranged between the resistance-voltage conversion circuit RT.sub.j and a first input terminal of the sense amplifier or between the reference circuit and RT.sub.R and a second input terminal of the sense amplifier. Current driving capability of the analog buffer circuit is large.

A memory device includes a plurality of data input/output (I/O) groups each including data I/O circuits, each data I/O circuit comprising a transistor having a predetermined threshold voltage according to a bulk voltage supplied to a bulk terminal thereof; a control circuit suitable for generating a control signal according to a data I/O mode; and a plurality of voltage supply circuits suitable for independently supplying bulk voltages to the plurality of data I/O groups, and changing, in response to the control signal, a level of a bulk voltage corresponding to data I/O groups unused in the data I/O mode, among the plurality of data I/O groups.

A memory device includes a plurality of data input/output (I/O) groups each including data I/O circuits, each data I/O circuit comprising a transistor having a predetermined threshold voltage according to a bulk voltage supplied to a bulk terminal thereof; a control circuit suitable for generating a control signal according to a data I/O mode; and a plurality of voltage supply circuits suitable for independently supplying bulk voltages to the plurality of data I/O groups, and changing, in response to the control signal, a level of a bulk voltage corresponding to data I/O groups unused in the data I/O mode, among the plurality of data I/O groups.

Control logic in a memory device initiates a read operation on a memory array of the memory device and performs a calibration operation to detect a change in string resistance in the memory array. The control logic determines whether the change in string resistance is attributable to charge loss in the memory array, and responsive to determining that the change in string resistance is attributable to charge loss in the memory array, preforms the read operation using calibrated read voltage levels to read data from the memory array.

Control logic in a memory device initiates a read operation on a memory array of the memory device and performs a calibration operation to detect a change in string resistance in the memory array. The control logic determines whether the change in string resistance is attributable to charge loss in the memory array, and responsive to determining that the change in string resistance is attributable to charge loss in the memory array, preforms the read operation using calibrated read voltage levels to read data from the memory array.