Semiconductor storage device and method of controlling the same
View Patent ↗An exemplary aspect of the present invention is a sense amplifier having a power supply voltage of 1.2 V or lower and amplifying a potential difference between a bit line pair, a first transistor supplying the power supply voltage to the sense amplifier, a second transistor supplying a low potential side voltage to the sense amplifier, and a control circuit controlling the first transistor to be a conduction state before the second transistor is set to the conduction state or at the same time when the second transistor is set to the conduction state.
1. A semiconductor storage device, comprising:
a sense amplifier having a power supply voltage of 1.2 V or lower and amplifying a potential difference between a bit line pair;
a first transistor supplying the power supply voltage to the sense amplifier;
a second transistor supplying a low potential side voltage to the sense amplifier; and
a control circuit controlling the first transistor to be a conduction state before the second transistor is set to the conduction state or at the same time when the second transistor is set to the conduction state.
2. The semiconductor storage device according to claim 1 , further comprising a third transistor connected to the first transistor in parallel and supplying a voltage higher than the power supply voltage, wherein
the third transistor is controlled by the control circuit to be the conduction state at the same time when the first transistor is set to the conduction state.
3. The semiconductor storage device according to claim 2 , wherein the third transistor is controlled by the control circuit to be a non-conduction state before a potential of one of the bit line pair reaches the power supply voltage.
4. The semiconductor storage device according to claim 1 , further comprising a fourth transistor connected to the second transistor in parallel and supplying a voltage lower than the low potential side power supply, wherein
the fourth transistor is controlled by the control circuit to be the conduction state at the same time when the second transistor is set to the conduction state.
5. The semiconductor storage device according to claim 4 , wherein the fourth transistor is controlled by the control circuit to be a non-conduction state before a potential of one of the bit line pair reaches the voltage of the low-potential side power supply.
6. A semiconductor storage device, comprising:
a memory cell connected to each of complementary bit lines;
a word line connected to the memory cell;
a sense amplifier connected between the complementary bit lines;
a first switch circuit selectively applying a first voltage of 1.2 V or lower to the sense amplifier;
a second switch circuit selectively applying a second voltage which is lower than the first voltage to the sense amplifier; and
a control circuit activating the first switch circuit earlier than the second switch circuit or at the same time when the second switch circuit is activated.
7. The semiconductor storage device according to claim 6 , further comprising a drive circuit driving the word line; wherein
the control circuit controls the drive circuit so that a timing at which the word line is activated is earlier than a timing at which the first switch circuit is activated.