Semiconductor integrated circuit
AssigneeRohm Co., Ltd.
InventorNaohiro Nomura
Life of this patent
Estimating the term…
Abstract
A semiconductor integrated circuit includes: a power supply pin configured to receive an external power supply voltage; a fuse memory circuit including a fuse element; and a power supply circuit, whose output is connected to the fuse memory circuit, configured to receive the external power supply voltage, the power supply circuit being switchable in response to a control signal between (i) a first state in which an internal power supply voltage of a first voltage level, which is capable of cutting the fuse element, is supplied to a power supply line of the fuse memory circuit and (ii) a second state in which the internal power supply voltage of a second voltage level lower than the first voltage level, which is incapable of cutting the fuse element, is supplied to the power supply line of the fuse memory circuit.
Claims11
A semiconductor integrated circuit, comprising:
- a power supply pin configured to receive an external power supply voltage;
- a fuse memory circuit including a fuse element;
- and
- a power supply circuit having an output connected to the fuse memory circuit, and configured to receive the external power supply voltage, the power supply circuit being switchable in response to a control signal between (i) a first state in which an internal power supply voltage of a first voltage level, which is capable of cutting the fuse element, is supplied to a power supply line of the fuse memory circuit and (ii) a second state in which the internal power supply voltage of a second voltage level lower than the first voltage level, which is incapable of cutting the fuse element, is supplied to the power supply line of the fuse memory circuit,
- wherein the power supply circuit includes a constant voltage circuit configured to be in a disable state in the first state, and be in an enable state in the second state and generate the internal power supply voltage of the second voltage level in the power supply line of the fuse memory circuit, and
- wherein the constant voltage circuit includes:
- a first transistor installed between the power supply pin and the power supply line of the fuse memory circuit;
- and
- a power supply control circuit configured to supply a control voltage to a control terminal of the first transistor.
A semiconductor integrated circuit, comprising:
- a power supply pin configured to receive an external power supply voltage;
- a fuse memory circuit including a fuse element;
- and
- a power supply circuit having an output connected to the fuse memory circuit, and configured to receive the external power supply voltage, the power supply circuit being switchable in response to a control signal between (i) a first state in which an internal power supply voltage of a first voltage level, which is capable of cutting the fuse element, is supplied to a power supply line of the fuse memory circuit and (ii) a second state in which the internal power supply voltage of a second voltage level lower than the first voltage level, which is incapable of cutting the fuse element, is supplied to the power supply line of the fuse memory circuit,
- wherein the power supply circuit includes a variable voltage circuit configured to generate the internal power supply voltage of the first voltage level in the power supply line of the fuse memory circuit in the first state and generate the internal power supply voltage of the second voltage level in the power supply line of the fuse memory circuit in the second state, and
- wherein the variable voltage circuit includes:
- a first transistor installed between the power supply pin and the power supply line of the fuse memory circuit;
- and
- a voltage control circuit configured to fully turn on the first transistor in the first state and feedback control a voltage of a control terminal of the first transistor so that the internal power supply voltage is brought close to the second voltage level in the second state.
Dependencies are inferred from the claim text.