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previous: Jimi I got a reply from Jack to my email... -- 9/11/1999 8:42 PM

Re:Minibooster Operation

9/16/1999 8:46 PM
John Greene	Re:Minibooster Operation It's interesting in the ap note that they use a FET with higher gain/higher cutoff voltage on top and a lower gain/lower cutoff voltage FET on the bottom. The top device has a VGSoff of -2 min whereas the bottom device has a VGSoff of -.6 min. The gain is roughly a 2 to 1 relationship. It also states that the lower the drain current the higher the gain however you sacrifice input dynamic ranger with increasing gain. Sounds like you could incorporate some sort of 'sag' mechanism using this characteristic. Says that it's sometimes called the "JFET u amp" because the voltage gain is dependent on the u of the bottom JFET (roughly half). u of a JFET increases as current decreases therefore the gain of the minibooster increases. FWIW, --johng

9/16/1999 8:46 PM

John Greene

Re:Minibooster Operation

It's interesting in the ap note that they use a FET with higher gain/higher cutoff voltage on top and a lower gain/lower cutoff voltage FET on the bottom. The top device has a VGSoff of -2 min whereas the bottom device has a VGSoff of -.6 min. The gain is roughly a 2 to 1 relationship.

It also states that the lower the drain current the higher the gain however you sacrifice input dynamic ranger with increasing gain. Sounds like you could incorporate some sort of 'sag' mechanism using this characteristic.

Says that it's sometimes called the "JFET u amp" because the voltage gain is dependent on the u of the bottom JFET (roughly half). u of a JFET increases as current decreases therefore the gain of the minibooster increases.

FWIW,

--johng

Replies:

Fuzzman >It also states that the lower the ... -- 9/16/1999 9:18 PM