FPGA (Field Programmable Gate Array) is an integrated circuit FPGA devices are produced by a number of semiconductor basic modes of programming: Antifuse-based FPGAs are different from the previous ones in that they can be. That is where the Field Programmable Gate Arrays (FPGAs) become of interest! They are hardware The antifuse programming technology is the simplest one. ❖The Programming technology. ❖The basic logic cells. ❖The I/O logic cells. ❖ Programmable interconnect. ❖Software to design and program the FPGA.
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Dielectric antifuses employ a very thin oxide barrier between a pair of conductors. This technology has many applications. Amorphous silicon is a material usually not used in either bipolar or CMOS processes and requires an additional manufacturing step. Whereas a fuse starts with a low resistance and is designed to permanently break an electrically conductive path typically antfuse the current through the path exceeds a specified limitan antifuse starts with a high resistance and is designed to permanently create an electrically conductive path typically when the voltage across the wntifuse exceeds a certain level.
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.
For example rpgas 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. When a sufficiently high voltage is applied antifuss the amorphous silicon it is turned into a polycrystalline silicon-metal alloy with a low resistancewhich is conductive.
This programming, performed after manufacturing, is permanent and irreversible. Each bit contains both a fuse and an antifuse and is programmed by triggering one of the two.
This page was last edited on 7 Julyat The larger, traditional, C7 and C9 style lights cpgas wired in parallel and are rated to operate directly at mains voltage. Also circuits built via the antifuse’s permanent conductive paths may be faster than similar circuits implemented in PLDs using SRAM technology.
The conductive shunt therefore does not compromise integrity and reliability of the semiconductor device. 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.
Ordinarily for operation from mains voltagesthe lamps are wired in series. Their disadvantage, however, is lower area efficiency compared to other types.
Views Read Edit View history. Because the series string would be rendered inoperable by a single lamp failing, each bulb has an antifuse installed within it. May Learn how and when to remove this template message.
Antifuse – Wikipedia
One approach for the ICs that use antifuse technology employs a thin barrier of non-conducting amorphous silicon between two metal conductors. An antifuse is an electrical device that performs the opposite function to a fuse. Unsourced material may be challenged and removed. Antifuses may be used in programmable read-only memory PROM. pfgas
Occasionally, the insulation fails to break down on its own, but tapping the blown lamp will usually finish the job.
In some cases a combined circuit with zeners and transistors can be used to form a zapping matrix; with additional zeners, the trimming which uses voltages higher than the normal operational voltage of the chip can be performed even after packaging the chip. The parallel resistors cannot have too low value as that would sink the zapping current; a series-parallel combination of resistors and antifuses is employed in such cases.
The terminals of the antifuses are usually accessible as bonding pads and the trimming process is performed before wire-bonding and encapsulating the chip. Certain programmable logic devices PLDssuch as structured ASICsuse antifuse technology to configure logic circuits and create a customized design from a standard IC design.
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.
From Wikipedia, the free encyclopedia. Antifuses are best known for their use in mini-light or miniature style low-voltage Christmas tree lights.
In this way, the failed lamp was bypassed and illumination restored to the rest of the street. As the number of bonding pads is limited for a given size of the chip, various multiplexing strategies are used for larger number of antifuses.
Each individual street-lamp was equipped with a film cutout ; a small disk of insulating film that separated two contacts connected to the two wires leading to the lamp. 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.
The spike is formed on and slightly below the silicon surface, just below the passivation layer without damaging it. Zener zap is frequently employed in mixed-signal circuits for trimming values of analog components. Antifuses are widely used to permanently program integrated circuits ICs. 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.
FPGAs in computer
Zener diodes can be used as antifuses. A specialized structure optimized for antifude purpose can be employed where the antifuse is an integral part of the design. 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.
Retrieved from ” https: With a poly-diffusion antifuse, the high current density creates heatwhich melts a thin insulating layer between polysilicon and diffusion electrodes, creating a permanent resistive silicon link. The p-n junction that serves as such diode is overloaded with a programmlng spike and overheated. The antifuse is made using wire with a high resistance coating and this wire is coiled over the two vertical filament support wires inside the bulb.
Formation of the conductive channel is performed by a dielectric breakdown forced by a high voltage pulse.
Often a special bulb with no antifuse and often a slightly different rating so it blows first as the voltage gets too high known as a “fuse bulb” is incorporated into the string of lights to protect against the possibility of severe overcurrent if too many bulbs fail.