Writing circuit for resistive random-access memory and method for writing to resistive random-access memory
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- RAMXEED LTD
- Filing Date
- 2022-12-12
- Publication Date
- 2026-06-23
AI Technical Summary
【0010】 抵抗変化素子の抵抗値を書き換える書き込み動作を、消費電力を増大させることなく精度よく行うことができる。
Smart Images
Figure 0007878041000001 
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Figure 0007878041000003
Abstract
Claims
1. A writing circuit for a resistive change memory having a resistive change element connected between a source line and a bit line, A reference resistor element with a fixed resistance value is connected between the reference source line and the reference bit line, The current mirror circuit includes a pair of current input terminals connected to the source line and the reference source line, respectively, and in a writing operation to increase the resistance of the resistance changing element, when the voltage of the source line is lower than the voltage of the reference source line, no current is drawn from the source line, and when the resistance changing element becomes more resistant due to the current flowing from the source line to the resistance changing element, and the voltage of the source line becomes higher than the voltage of the reference source line, the shunt circuit draws current from the source line. A programming circuit for resistive random-access memory.
2. The current mirror circuit described above is A first transistor of first polarity, whose source is connected to the source line, A first-polarity second transistor, the source of which is connected to the reference source line and the gate and drain of which are connected to the gate of the first transistor, A third transistor of second polarity, whose drain and gate are connected to the drain of the first transistor and whose source is connected to a low-voltage line, The fourth transistor has a second polarity, the drain of which is connected to the drain of the second transistor, the gate of which is connected to the gate of the third transistor, and the source of which is connected to the low voltage line. A writing circuit for a resistive change memory according to claim 1.
3. A fifth transistor of first polarity is connected between a high-voltage line supplied with high voltage and the source line, A sixth transistor of first polarity is connected between the high-voltage line and the reference source line, A detection unit that detects the transition of the gate voltage of the first transistor from a high level to a low level, The system includes a voltage application unit that applies a voltage to the gates of the fifth and sixth transistors to turn them on before the detection unit detects the transition of the gate voltage to a low level, and applies the high voltage to the gates of the fifth and sixth transistors based on the detection unit's detection of the low level. A writing circuit for a resistive change memory according to claim 2.
4. A first transfer transistor connected between the resistive switching element and the bit line, A second transfer transistor connected between the reference resistor element and the reference bit line, A seventh transistor of second polarity receives a control signal supplied to the gate of the first transfer transistor at its gate, and turns off when the first transfer transistor turns off, The system includes an eighth transistor of second polarity that receives the aforementioned control signal at its gate and turns off when the first transfer transistor turns off, The source of the third transistor is connected to the low-voltage line via the seventh transistor. The source of the fourth transistor is connected to the low-voltage line via the eighth transistor. A writing circuit for a resistive change memory according to claim 2 or claim 3.
5. A current supply unit that supplies current to the source line and the reference source line, respectively, The current control unit controls the current supply unit to supply current to the source line and the reference source line while the shunt circuit detects that the voltage of the source line is lower than the voltage of the reference source line during the writing operation, and cuts off the supply of current to the source line and the reference source line when the shunt circuit detects that the voltage of the source line has become higher than the voltage of the reference source line. A writing circuit for a resistive change memory according to claim 1.
6. A method for writing to a resistive change memory having a resistive change element connected between a source line and a bit line, and a reference resistor element with a fixed resistance value connected between a reference source line and a reference bit line, A shunt circuit, which includes a current mirror circuit with a pair of current input terminals connected to the source line and the reference source line respectively, performs a write operation to increase the resistance of the resistance-changing element. When the voltage of the source line is lower than the voltage of the reference source line, it does not draw current from the source line. When the resistance-changing element becomes more resistant due to the current flowing from the source line to the resistance-changing element, and the voltage of the source line becomes higher than the voltage of the reference source line, it draws current from the source line. How to write to resistive random-access memory.