Apparatus and methods for protection against inadvertent programming of fuse cells
First Claim
1. A fuse system for a semiconductor die, the fuse system comprising:
- a fuse protection diode;
a first fuse;
a first fuse programming transistor and a first cascode transistor electrically connected in series between a cathode of the fuse protection diode and the first fuse;
a power supply pad electrically connected to an anode of the fuse protection diode, the power supply pad configured to receive a power supply voltage; and
a biasing circuit powered by the power supply voltage and including a voltage regulator configured to generate a regulated voltage and a level shifter configured to provide a fuse programming signal to a gate of the first fuse programming transistor, the level shifter configured to control the fuse programming signal with the power supply voltage in a first state of a control signal, and to control the fuse programming signal with the regulated voltage in a second state of the control signal.
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Accused Products
Abstract
Apparatus and methods for protection against inadvertent programming of fuse cells are provided herein. In certain configurations, a fuse system includes a fuse protection diode, a fuse, a fuse programming transistor and a cascode transistor electrically connected in series between a cathode of the fuse protection diode and the fuse, a power supply pad electrically connected to an anode of the fuse protection diode and that receives a power supply voltage, and a biasing circuit powered by the power supply voltage and including a voltage regulator that generates a regulated voltage and a level shifter that provides a fuse programming signal to a gate of the fuse programming transistor. The level shifter controls the fuse programming signal with the power supply voltage in a first state of a control signal, and controls the fuse programming signal with the regulated voltage in a second state of the control signal.
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Citations
20 Claims
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1. A fuse system for a semiconductor die, the fuse system comprising:
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a fuse protection diode; a first fuse; a first fuse programming transistor and a first cascode transistor electrically connected in series between a cathode of the fuse protection diode and the first fuse; a power supply pad electrically connected to an anode of the fuse protection diode, the power supply pad configured to receive a power supply voltage; and a biasing circuit powered by the power supply voltage and including a voltage regulator configured to generate a regulated voltage and a level shifter configured to provide a fuse programming signal to a gate of the first fuse programming transistor, the level shifter configured to control the fuse programming signal with the power supply voltage in a first state of a control signal, and to control the fuse programming signal with the regulated voltage in a second state of the control signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of protecting against accidental fuse programming, the method comprising:
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providing a power supply voltage to a power supply pad, the power supply pad connected to an anode of a fuse protection diode; powering a biasing circuit that biases a fuse programming transistor using the power supply voltage, the fuse programming transistor electrically connected in series with a cascode transistor between a cathode of the fuse protection diode and a fuse; generating a regulated voltage using a voltage regulator of the biasing circuit; and providing a gate of the fuse programming transistor with a fuse programming signal from a level shifter of the biasing circuit, including controlling the fuse programming signal with the power supply voltage in a first state of a control signal, and controlling the fuse programming signal with the regulated voltage in a second state of the control signal. - View Dependent Claims (12, 13, 14)
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15. A packaged module comprising:
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a package substrate; and a semiconductor die attached to the package substrate, the semiconductor die including a fuse protection diode, a first fuse, a first cascode transistor, a first fuse programming transistor electrically connected in series with the first cascode transistor between a cathode of the fuse protection diode and the first fuse, a power supply pad electrically connected to an anode of the fuse protection diode and configured to receive a power supply voltage, and a biasing circuit powered by the power supply voltage and including a voltage regulator configured to generate a regulated voltage and a level shifter configured to provide a fuse programming signal to a gate of the first fuse programming transistor, the level shifter configured to control the fuse programming signal with the power supply voltage in a first state of a control signal, and to control the fuse programming signal with the regulated voltage in a second state of the control signal. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification