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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In a similar fashion to ajtifuse of Christmas foga lights, before the advent of high-intensity discharge lampsstreet light circuits using incandescent light bulbs were often operated as high-voltage series circuits. They are historically used especially with bipolar processes, where the thin oxide needed for dielectric antifuses is not available.
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. 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. By this approach, it is possible only to lower the value of the resulting resistor.
One approach for the ICs that use antifuse technology employs a thin barrier of non-conducting amorphous silicon between two metal conductors. Dielectric antifuses employ a very thin oxide barrier between a pair of conductors.
Antifuse – Wikipedia
Certain programmable logic devices PLDssuch as structured ASICsuse antifuse technology to configure logic circuits and create a customized design from a standard IC design.
The terminals of the antifuses are usually accessible as bonding pfga and the trimming process is performed before wire-bonding and encapsulating the chip.
Each bit contains both a fuse and an antifuse and is programmed by triggering one of the two. When the failed lamp was natifuse changed, a new piece of film was antiduse installed, once again separating the electrical contacts in the cutout.
This page was last edited on 7 Julyat Fga material may be challenged and removed.
The p-n junction that serves fpgx such diode is overloaded with a current spike and overheated. Antifuses may be used in programmable read-only memory PROM. 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. When the bulb blows, the entire mains voltage is applied across the single blown lamp.
antifuse Definition from PC Magazine Encyclopedia
This technology has many applications. The conductive shunt therefore does not compromise integrity and reliability of the semiconductor device. Retrieved from ” https: 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.
The larger, traditional, C7 and C9 style lights are wired in parallel and are rated to operate directly at mains voltage. Amorphous silicon is a material usually not used in either bipolar or CMOS processes and requires an additional manufacturing step.
Zener zap is frequently employed in mixed-signal circuits for trimming values of analog components. The insulation of the antifuse wire withstands the ordinary low voltage imposed across a functioning lamp but rapidly breaks down under the full mains voltage, giving the antifuse action.
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. Occasionally, the insulation fails to break down on its own, but tapping the blown lamp will usually finish the job. Antifuses are widely used to permanently program integrated circuits ICs. In this way, the failed lamp was bypassed and illumination restored to the rest of the street.
In the same fashion as with the Christmas lights described above, if the flga 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. Their disadvantage, however, is lower area efficiency compared to other types. Antifuses are best known for their use in mini-light or miniature style low-voltage Christmas tree lights.
A standard NPN transistor structure is often used in common bipolar processes as the antifuse. Formation of the conductive channel is performed by a dielectric breakdown forced by a high voltage pulse. This programming, performed after manufacturing, is permanent and irreversible. 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.
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 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. 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. They may be less susceptible to alpha particles which can cause circuits to malfunction.
Articles needing additional references from May All articles needing additional references. Zener diodes can be used as antifuses. Whereas a fuse starts with a low resistance and is designed to permanently break an electrically conductive path typically when 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 antifuse exceeds a certain level.
Also circuits built via the antifuse’s permanent conductive paths may be faster than similar circuits implemented in PLDs using SRAM technology.