The antifuse technology, routing architecture, logic mod- ule, design automation, programming, testing and use of ACTTM antifuse FPGA ‘s are described. FPGA Architectures Overview. In this short article we discuss modern FPGA architectures (SRAM-based, flash-based, antifuse- based) and their applications. Imperial College, Digital System Design. Actel FPGAs. ◇ Uses antifuse technology. ◇ Based on channelled gate array architecture as shown below.
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This technology has many applications. Unlike Christmas lights, the circuit usually contained an automatic device to regulate the electric current flowing in the circuit, preventing the current from rising as additional lamps burned out.
The terminals of the antifuses are usually accessible as bonding pads and the trimming process is performed before wire-bonding and encapsulating the chip. This programming, performed after manufacturing, is permanent and irreversible. The parallel resistors cannot have too low value as that would sink the zapping fppga a series-parallel combination of resistors and antifuses is employed in such cases.
antifuse Definition from PC Magazine Encyclopedia
In some cases a combined circuit with zeners and transistors can be used to form a zapping matrix; with additional antifuss, the trimming which uses voltages higher than the normal operational voltage of the chip can be performed even after packaging the chip. Unsourced material may be challenged and removed. The insulation of the antifuse wire withstands the ordinary low voltage imposed across a functioning lamp but rapidly breaks down under the antifusr mains voltage, giving the antifuse action.
The conductive shunt therefore does not compromise integrity and reliability of the semiconductor device. The resulting resistance of the junction is in the range of 10 ohms. The larger, traditional, C7 and C9 style lights are wired in parallel and are rated to operate directly at mains voltage.
Antifuses may be used in programmable antfiuse memory PROM. This page was last edited on 7 Julyat Please help improve this article by adding citations to reliable sources. Antifuses are best known for their use in mini-light or miniature style low-voltage Christmas tree lights.
The antifuse is usually triggered using an approximately 5 mA current. Antifuses are widely used to permanently program integrated circuits ICs. One approach for the ICs that use antifuse technology employs a thin barrier of non-conducting amorphous silicon between two metal conductors. Their disadvantage, however, is lower area efficiency compared to other types.
Ordinarily for operation from mains voltagesthe lamps are wired in series.
In the same fashion as with the Christmas lights described above, if the lamp failed, the entire voltage of the street lighting circuit thousands of volts was imposed across the insulating film in the cutout, causing it to rupture. When the bulb blows, the entire mains voltage is applied across the single blown lamp.
Views Read Edit View history. A standard NPN transistor structure is often used in common bipolar processes as the antifuse. This rapidly causes the antifuse to short out the blown bulb, allowing the series circuit to resume functioning, albeit with a larger proportion of the mains voltage now applied to each of the remaining lamps.
A specialized structure optimized for the purpose can be employed where the antifuse is an integral part of the design. The spike is formed on and slightly below the silicon surface, just below the passivation layer without damaging it.
Amorphous silicon is a material usually not used in either bipolar or CMOS processes and requires an additional manufacturing step. QuickLogic Corporation refers to their antifuses as “ViaLinks” because blown fuses create a connection between two crossing layers of wiring on the chip in the same way that a via on a printed circuit board creates a connection between copper layers.
Each bit contains both a fuse and an antifuse and is programmed by triggering one of the two. When the failed lamp was finally changed, a new piece of film was also installed, once again separating the electrical contacts in the cutout. It is therefore necessary to shift the manufacturing tolerances so that the lowest-value typically made is equal to or larger than the desired value.
From Wikipedia, the free encyclopedia. For example a precision resistor can be manufactured by forming several series resistors with Zeners in parallel oriented to be nonconductive during normal operation of the device and then shorting selected Zeners to shunt the unwanted resistors.
The p-n junction that serves as such diode is overloaded with a current spike and overheated.
An antifuse is an electrical device that performs the opposite function to a fuse. In this way, the failed lamp was bypassed and illumination restored to the rest of the street.
May Learn how and when to remove this template message. This article needs additional citations for verification. Occasionally, the insulation fails to break down on its own, but tapping the blown lamp will usually finish the job. Because the series string would be rendered inoperable by a single lamp failing, each bulb has an antifuse installed within antifsue.
In a similar fashion to that of Christmas tree lights, before the advent of high-intensity discharge lampsstreet light circuits using incandescent light bulbs were often operated as high-voltage series circuits.
Fppga the number of bonding pads is limited for a given size of the chip, various multiplexing strategies are used for larger number of antifuses.