Help required to improve this circuit

[jayce3390]

Hi,

I need suggestions to improve the speed of this circuit. This is a circuit able to translate a voltage level from 0/5V to 0/70V.

A transient simulation shows 1 us of delay time between input and output, it's really slow.

 

[elockpicker]

maybe u can use diodes with faster propagation delay.

 

[LordAli]

Hard to say. Used components are really pretty fast. Try to put 100 - 1000 pF capacitor across diode D1. If it don't help try to find special fast switching transistors (for oscilloscopes for example) not general purpose transistors. Some better datasheets have switching times. I couldn't find it in datasheets of your components.