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rajesh14 New Member Offline Posts: 6 tuni, andhra pradesh	about breakdown voltage Nov 06^th, 2009, 9:06am can anybody say how breakdown voltage of a particular device plays an important role in RF/ANALOG Applications..?
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HdrChopper Community Fellow Offline Posts: 493	Re: about breakdown voltage Reply #1 - Nov 6^th, 2009, 6:53pm Hi rajaesh, Your question sounds like too broad. From a general perspective I think it becomes an important parameter every time the device in question goes conneted to an input/output pin, where high voltages might hit the circuit.... Best Tosei
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Mayank

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Re: about breakdown voltage
Reply #2 - Nov 9^th, 2009, 11:10am

Hello rajesh,
The break-down voltage is a limiting voltage above which Source & Drain starts exhibiting very high conductance because of avalanche/Zener Breakdown Effect...In all applications including RF/Analog, we always operate much below the breakdown Voltage.....
Special care must be taken to ensure that voltage across any two MOS terminals should not go above the rated operation voltage(like 3.3V mos, 2.4V MOS, 1.2V MOS)....Esp in the case of a change in supply domain, like at the inputs as Tosei suggested, we place special ESD/CDM devices to ensure that the MOSFETs never come under stress....
i think that should suffice....

--Mayank

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HdrChopper

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Re: about breakdown voltage
Reply #3 - Nov 9^th, 2009, 5:53pm

The temperature dependence of the BK voltage depends on whether it is Zener or avalanche. Zener BK depends on tunneling effect and its voltage decreases with temperature, while avalanche depends on impact ionization and thus the BK voltage increases with temperature.

Those temperature coefficients are sometimes used as reference voltages for some temp compensation circuits. That is another role that sometimes the breakdown voltage plays in analog design.

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Tosei

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Mayank Community Fellow Offline Posts: 334	Re: about breakdown voltage Reply #4 - Nov 9^th, 2009, 8:33pm Hello Tosei, You mean as the reverse Breakdown Voltage in Zener Diodes used in reference ckts sometimes ?? --Mayank
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HdrChopper Community Fellow Offline Posts: 493	Re: about breakdown voltage Reply #5 - Nov 10^th, 2009, 3:57am Yes... Gray and Meyer classic text book shows some examples of those. Best Tosei
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