Semiconductor integrated circuit device
First Claim
1. A semiconductor integrated circuit device having a memory circuit comprising:
- a memory array including;
a plurality of word lines,a first dummy word line,a second dummy word line,a plurality of bit lines across the plurality of word lines, the first dummy word line, and the second dummy word line,a plurality of memory cells each having a first capacitor and a first MOSFET, a source and a drain of the first MOSFET being coupled between one of the plurality of bit lines and a storage node of the first capacitor, and a gate of the first MOSFET being coupled to one of the plurality of word lines, anda plurality of dummy memory cells each having a second capacitor, a second MOSFET, and a third MOSFET, a source and a drain of the second MOSFET being coupled between one of the plurality of bit lines and a storage node of the second capacitor, a gate of the second MOSFET being coupled to the first dummy word line, a source and a drain of the third MOSFET being coupled between the storage node of the second capacitor and a reference voltage, and a gate of the third MOSFET being coupled to the second dummy word line;
a plurality of sense amplifiers each provided corresponding to one of the plurality of bit lines, sensing a difference between a signal read out from a selected memory cell and a signal read out from one of the plurality of dummy memory cells, and amplifying the signal read out from the selected memory cells to a first voltage or a second voltage; and
a precharge circuit supplying the first voltage to the plurality of bit lines,wherein the reference voltage is between the first voltage and the second voltage.
0 Assignments
0 Petitions
Accused Products
Abstract
The present invention provides a dynamic RAM which can be operated at a low voltage and realizes the enhancement of a read margin and an area-saving layout. In a memory array including a plurality of memory cells having capacitors which are formed corresponding to a plurality of word lines and a plurality of bit lines, stored information of the memory cell which is read to one bit line out of the pair of bit lines is sensed by a sense amplifier in response to a reference voltage which is formed by a dummy cell connected to another bit line, a precharge voltage of high level or low level corresponding to an operational voltage by a precharge circuit is supplied to the bit lines, and the dummy cells having the same structure as the memory cells are formed at crossing points of word lines for dummy cells and bit lines arranged outside the memory array, MOSFETs which precharge an intermediate voltage between the high level voltage and the low level voltage to the capacitors are provided, and gates of the MOSFETs are connected with charge word lines for dummy cells which are extended in parallel with the word lines for dummy cells.
15 Citations
9 Claims
-
1. A semiconductor integrated circuit device having a memory circuit comprising:
-
a memory array including; a plurality of word lines, a first dummy word line, a second dummy word line, a plurality of bit lines across the plurality of word lines, the first dummy word line, and the second dummy word line, a plurality of memory cells each having a first capacitor and a first MOSFET, a source and a drain of the first MOSFET being coupled between one of the plurality of bit lines and a storage node of the first capacitor, and a gate of the first MOSFET being coupled to one of the plurality of word lines, and a plurality of dummy memory cells each having a second capacitor, a second MOSFET, and a third MOSFET, a source and a drain of the second MOSFET being coupled between one of the plurality of bit lines and a storage node of the second capacitor, a gate of the second MOSFET being coupled to the first dummy word line, a source and a drain of the third MOSFET being coupled between the storage node of the second capacitor and a reference voltage, and a gate of the third MOSFET being coupled to the second dummy word line; a plurality of sense amplifiers each provided corresponding to one of the plurality of bit lines, sensing a difference between a signal read out from a selected memory cell and a signal read out from one of the plurality of dummy memory cells, and amplifying the signal read out from the selected memory cells to a first voltage or a second voltage; and a precharge circuit supplying the first voltage to the plurality of bit lines, wherein the reference voltage is between the first voltage and the second voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification