>100M iopad ESD protection?

[wxsimon]

any idea?
wide mosfet or diode?
parasitic capacitor of mosfet or resistor harmful?
Need suggestion, thx!

 

[sunjimmy]

Hi,

To survive under this high 100MV stress,
the protection device (no matter diode/mosfet) must turn ON as mamy as possible during ESD stress. You probably need some triger ckt to help all protection device turn ON as fast & as mamy as possible. There are some ESD papers talking about this issue, you may find them on the forum.

Hope it helps

 

[wxsimon]

Thanks for reply first.
Sorry for my title is not clear.
My question is frequency > 100MHz, may parasitic capacitors of ESD protection devices harmful?

 

[flatulent]

usual trick

The usual trick for dealing with a shunt capacitance is to adjust a series inductance so that a low pass filter is formed with flat response. This does not always work since the filter may cut off your signal.

 

[LONG]

u ensure the problem is on signal line or on GND!
more ESD had come into being GND.

 

[sunjimmy]

Hi,

I found 2 papers which address what you want;

1.IEEE Journal of Solid-State circuits June 2002 pp760
"A 0.8-dB NF ESD-Protected 9-mW CMOS LNA Operating at 1.23GHz"

2.IEEE Journal of Solid-State circuits Aug. 2000 pp1194
"ESD Protection Design on Analog Pin with very Low Input Capacitance for High-frequency or Current-Mode Application"
- This paper shows 1pF input capacitance which should be good enough for 100MHz operation.

Hope it helps