fast level Shift 5V to 40V ?

[hervehman]

Hello,

How to make fast (<10ns) level Shift from 5 to 40V ?

Thanks all !

 

[chuckey]

I doubt if you can do it. What you need is one (or more) RF power transistors to charge/discharge the capacitance on the output terminal. It would be helpful if we knew what the load impedance was.
Frank

 

[hervehman]

Hi, and thanks for the answer.

The load will be small BJT or MOS gate. Let say <10pF. I already found some IC solutions:
- "light" low side gate driver, but it hardly reach more than 20V,
- Same with some CMOS comparator.
- Low and High side gate driver, any voltage but a bit slower.
- the old CD4000 family (20ns under 18V)
- CMOS Push pull current conveyor. It will require strong biasing current.
- Bistable topology, 2 Inverters stages driving each other. Small impulsion should switch form one state to an other. The second inverter will help driving the first one and thus avoid those strong biasing currents.

I was wondering if some well known solution already exists, was already used, if some specific IC will do the Job.

 

[dick_freebird]

Power MOSFET drivers or bridge drivers may do this but
generally they are not so fast. At the 40V node, BJTs
are good for less than 1GHz fT pretty much, and that's
if you're really careful about preventing saturation. 40V
MOS is even slower.

Anyway, I think I'd look at high side FET drivers or using
a section of a half-bridge or full-bridge driver.