Otptofets
in [Design]
|
From: Jon Slaughter on 17 Feb 2010 18:46 Are there devices that are fet based and have optical isolation? e.g., maybe something that uses a transformer to isolate the gate? I remember seeing, I think from TI, some very small transformer isolation IC's and I imagine one could combine this with a fet to get some pretty responsive isolation like behavior(obviously in this cause it's not optics involved).
From: John Larkin on 17 Feb 2010 19:21 On Wed, 17 Feb 2010 17:46:01 -0600, "Jon Slaughter" <Jon_Slaughter(a)Hotmail.com> wrote: >Are there devices that are fet based and have optical isolation? e.g., maybe >something that uses a transformer to isolate the gate? I remember seeing, I >think from TI, some very small transformer isolation IC's and I imagine one >could combine this with a fet to get some pretty responsive isolation like >behavior(obviously in this cause it's not optics involved). > > > Analog Devices and TI both make logic isolators that are very fast. The ADI parts are inductively coupled, and the TIs are capacitive. Some of the ADI parts include a power isolator too, which can be very handy. John
From: Martin Riddle on 17 Feb 2010 21:15 "John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message news:rp1pn5hmcfrvpiiv6kqb8k8g69dcee4q3e(a)4ax.com... > On Wed, 17 Feb 2010 17:46:01 -0600, "Jon Slaughter" > <Jon_Slaughter(a)Hotmail.com> wrote: > >>Are there devices that are fet based and have optical isolation? e.g., >>maybe >>something that uses a transformer to isolate the gate? I remember >>seeing, I >>think from TI, some very small transformer isolation IC's and I >>imagine one >>could combine this with a fet to get some pretty responsive isolation >>like >>behavior(obviously in this cause it's not optics involved). >> >> >> > > Analog Devices and TI both make logic isolators that are very fast. > The ADI parts are inductively coupled, and the TIs are capacitive. > > Some of the ADI parts include a power isolator too, which can be very > handy. > > John > The ADI power isolators are good for 100ma. Cheers
From: Okkim Atnarivik on 18 Feb 2010 04:52 Jon Slaughter <Jon_Slaughter(a)hotmail.com> wrote: : Are there devices that are fet based and have optical : isolation? e.g., maybe something that uses a transformer : to isolate the gate? You don't mean such devices as the Panasonic AQY221 or Toshiba TLP3250 ? There is a photodiode illuminated by the LED, and the photodiode current drives the gate of a MOSFET switch. Slow, but convenient relay substitutes. Regards, Mikko
From: John Fields on 18 Feb 2010 09:26
On Wed, 17 Feb 2010 17:46:01 -0600, "Jon Slaughter" <Jon_Slaughter(a)Hotmail.com> wrote: >Are there devices that are fet based and have optical isolation? e.g., maybe >something that uses a transformer to isolate the gate? I remember seeing, I >think from TI, some very small transformer isolation IC's and I imagine one >could combine this with a fet to get some pretty responsive isolation like >behavior(obviously in this cause it's not optics involved). --- http://www.fairchildsemi.com/ds/H1%2FH11F1M.pdf JF |