Back to results
US 6,611,468 B2Granted
Non-volatile semiconductor memory device having sensitive sense amplifier structure
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsIsao Nojiri, Atsushi Ohba, Yoshihide Kai
Life of this patent
Estimating the term…
Abstract
In a non-volatile semiconductor memory device, a constant current circuit is arranged in parallel with an NMOS diode converting a detected current on the array cell side to a voltage, and a constant current circuit is arranged in parallel with an NMOS diode converting a detected current on the reference cell side to a voltage. Constant current circuits supply an offset current. Thus, a difference between two input voltages of a differential amplifier increases.
Claims13
A non-volatile semiconductor memory device, comprising:
- a non-volatile memory cell;
- a reference cell for determining storage data of said non-volatile memory cell;
- a differential amplifier for detecting a difference between voltages at first and second input nodes;
- a first current voltage converting element connected to said first input node for converting a first read current from said non-volatile memory cell to a voltage;
- a second current voltage converting element connected to said second input node for converting a second read current from said reference cell to a voltage;
- and
- a gain adjusting circuit for adjusting a detection sensitivity of said differential amplifier by adjusting values of said first and second read currents by substantially the same value, said gain adjusting circuit including a constant current circuit for supplying offset currents to said first and second input nodes.
4 more elements
A non-volatile semiconductor memory device, comprising:
- a non-volatile memory cell;
- a reference cell for determining storage data of said non-volatile memory cell;
- a differential amplifier detecting a difference between voltages at first and second input nodes;
- a first current voltage converting element connected to said first input node for converting a first read current from said non-volatile memory cell to a voltage;
- a second current voltage converting element connected to said second input node for converting a second read current from said reference cell to a voltage;
- and
- a gain adjusting circuit for adjusting a detection sensitivity of said differential amplifier by adjusting values of said first and second read currents by substantially the same values wherein said gain adjusting circuit comprises:
- a drive circuit for generating a current having a value lower than that of said second read current based on said second read current and for converting said generated current to a voltage,
- a first element connected to said first input node for supplying a first offset current based on the voltage obtained from said drive circuit, and
- a second element connected to said second input node for supplying a second offset current based on the voltage obtained from said drive circuit.
7 more elements
A non-volatile semiconductor memory device, comprising:
- a non-volatile memory cell;
- a reference cell for determining storage data of said non-volatile memory cell;
- a differential amplifier for detecting a difference between voltages at first and second input nodes;
- a first current voltage converting element connected to said first input node for converting a first read current from said non-volatile memory cell to a voltage;
- a second current voltage converting element connected to said second input node for converting a second read current from said reference cell to a voltage;
- and
- a gain adjusting circuit for adjusting a detection sensitivity of said differential amplifier by adjusting values of said first and second read currents by substantially the same value wherein said gain adjusting circuit comprises:
- a drive circuit for generating a current having a value lower than said second read current based on said second read current based on said second read and for converting said generated current to a voltage,
- first element connected to said first input node for supplying a current having a value lower than that of said second read current to said second current voltage converting element, and
- a second element connected to said second input node for supplying an offset current based on the voltage obtained from said drive circuit.
7 more elements
A non-volatile semiconductor memory device, comprising:
- a non-volatile memory cell capable of operating in storage states, said n is an integer of at least 3;
- k reference cells for determining said n storage states, said k is an integer of at least 2;
- k first current voltage converting elements each converting a first read current of said non-volatile memory cell to a voltage;
- k second current voltage converting elements converting said k second read currents from said k reference cells to voltages;
- k differential amplifiers detecting differences between respective outputs from said k first current voltage converting elements and respective outputs from said k second current voltage converting elements;
- and
- a gain adjusting circuit adjusting each detection sensitivity of said k differential amplifiers by adjusting values of said k second read currents and said first read current,
- wherein said k first current voltage converting elements and said k second current voltage converting elements respectively include diode elements or resistive elements, and said gain adjusting circuit includes a constant current circuit for reducing input currents to said k first current voltage converting elements and at least one of said k second current voltage converting elements.
5 more elements
Dependencies are inferred from the claim text.