Help with replacing transistor with faster speed

[globalone]

**broken link removed**

Hello,

I am building a fast switch driver circuit . Switching speeds are similar to the bipolar design.

The circuit provides 35nSec rise and fall times. This circuit will turn the switch on and off within 50nSec.

My target is to have faster speed for Turn-On/Turn-Off . 35nSec would be okay for the T-On/T-OFF , but I want to reach between 15nSec ~ 30nSec.

Do you think that BSS84DW (**broken link removed**) can be replaced with NDC7003P or NDS9948 ?.

What speed would i reach If I am going to use NDC7003P or NDS9948 ?.
https://www.fairchildsemi.com/ds/ND/NDC7003P.pdf
https://www.fairchildsemi.com/ds/ND/NDS9948.pdf

I want to provide the circuit with a negative supply between -40V to -50V.

I appreciate your help


Regards,
Ghassan

 

[crutschow]

I would think those would work. The 7003 seems slightly faster.

You Attachment is invalid.

 

[globalone]

I would think those would work. The 7003 seems slightly faster.

You Attachment is invalid.

Hello again,

Thank you so much for your recommendation , but I am only worried about the speed if I am going to bias -40V or -50V with -5V . I have attached the circuit again with different way.

Can you please let me know if you are able to see the circuit well.



- - - Updated - - -

Should i just use the same resistors with the 7003 , because i believe -5v would have different speed for turn-on & turn off speeds ?

 

[globalone]

Are you familiar with (DUAL P-CHANNEL ENHANCEMENT MODE MOSFET). I have a working circuit that accept a logic input (0V/+5V) to bias a switch VC1 & VC2 (0V/-40V).

I had to use BSS84DW (**broken link removed**) , but the circuit provide a switching speed on and off within 50nSec and rise/fall 35nSec.


I have already found a replacement to BSS84DW with NDC7003P (https://www.fairchildsemi.com/ds/ND/NDC7003P.pdf) which should be faster , but I am not sure if it will use the same resistors , capacitors etc..

I want to know what should I get a Turn-OFF/Turn-ON speed if I am going to use the new PowerTrench MOSFET (NDC7003P) ?.


I really appreciate your help