Other Parts Discussed in Thread: LM5022
I am looking for a boost converter to convert 24V (BAT) => 80V to over-drive a LED array (Vf ~ 80V - If ~ 4.9A - rD = 3.56 Ohm) at pulse width of about 200us (f ~ 20Hz).
I have run some tests using LM3429, injecting the pulse at nDIM (pin-7) but I cannot get a good response time from the driver at 200us pulse width. It works pretty well down to 1-2ms range pulse width but seems slow for 200us pulse.
I am wondering what would you recommend for over-driving a LED array (Vf ~ 80V - If ~ 4.9A - rD = 3.56 Ohm - pulse width ~ 200us - f ~ 20Hz)?
#1 - Using the nDIM of an LED driver such as LM3429 (using PWM input for pulse mode operation)
#2 - Using a boost converter such as LM5022 at about 0.6A, charging a big cap and then using a switch to dump the big cap charge into giant LED. Probably this method needs a minimum load, true?
#3 - If I use a LED driver (i.e. LM3429) and keep the LED driver in continuous mode (always running nDIM=Hi) and control the big LED array (load) using an NMOS low side switch (100us, short pulse controls the NMOS gate) then does it make a difference to use a boost converter (i.e. LM5022) instead of LED driver (i.e. LM3429)?
In other words what is the difference between using a LED driver (i.e. LM3429) vs a boost (i.e.LM5022) about what I described above, would it be the same?
Please let me know your thoughts.