Time : Apr 28 2022Source :Analog Technologies, Inc. Author : ATI Click :
How an Amplifier Drives a Capacitive Load
Consider a single pulse = one rise and one fall
Charge transfer on each transition = CIoad •ΔVout = lrise •Trise = lfall•Tfall
Energy dissipated in Qhigh = average voltage • current• time
=(Vbus-Vout_avg)•lrise •Trise
=(Vbus-Vout_avg)•CIoad •ΔVout
Energy dissipated in Qlow = average voltage• current• time
= Vout_avg • lfall•Tfall
= Vout_avg •CIoad •ΔVout
Total energy dissipated in Qhigh and Qlow = (Vbus-Vout_avg)•CIoad •ΔVout + Vout_avg •CIoad •ΔVout
= CIoad •Vbus•ΔVout
For repeated pulses;
Total power dissipated in Qhigh and Qlow = CIoad •Vbus•ΔVout•frequency
Example:100pF•2500V•400V•20kHz=2W
Thanks for Ed Solomon, Triple Ring Technologies Inc.
Keywords: high voltage amplifier, high voltage amplifiers, high speed high voltage amplifier
