Semiconductor device
AssigneeRenesas Electronics Corporation
InventorsKoichi Takeda, Akihiko Kanda, Takahiro Shimoi
Life of this patent
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Abstract
A clamp element 46 applies a fixed potential to a bit line BL at a time of a readout operation. A reference current source RCS generates a reference current Iref. An offset current source OCS1 is activated at a time of a readout operation for an OTP cell OTPC, and at a time of being activated, generates an offset current Iof1 to be subtracted from a cell current Icel. At the time of the readout operation for the OTP cell OTPC, the sense amplifier SA detects a magnitude relationship between the reference current Iref and a readout current Ird obtained by subtracting the offset current Iof1 from the cell current Icel.
Claims8
A semiconductor device comprising:
- a bit line;
- a first memory cell that is connected to the bit line and includes a first storage element of a variable resistance type;
- a second memory cell that is connected to the bit line, includes a second storage element having same electrical characteristics as the first storage element, and is used as a One Time Programmable (OTP) cell;
- a clamp element configured to apply a fixed potential to the bit line at a time of a readout operation;
- a reference current source configured to generate a reference current;
- a sense amplifier configured to apply the fixed potential to the first memory cell or the second memory cell at the time of the readout operation to detect, by using the reference current, a magnitude of a cell current flowing through the bit line;
- and
- an offset current source that is activated at a time of the readout operation for the second memory cell, and is configured to generate, at a time of being activated, an offset current to be subtracted from the cell current,
- wherein, at the time of the readout operation for the second memory cell, the sense amplifier detects a magnitude relationship between the reference current and a readout current obtained by subtracting the offset current from the cell current.
Dependencies are inferred from the claim text.