Driving long LED strings from a 160VDC Bus

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I need to drive several long (~30-40 LED in series) LED strings from a 160VDC Bus.


Are there any switch mode IC's out there suited do this?

Preferably i wish the strings to be switched equally phase shifted from each other, so that ripple current drawn from the bus is minimised.
 

Yes there are LED drivers available from manufacturers like TI, Micrel, LinearTech etc. I have seen upto 10 in series LED drivers, there may be available for 30-40 devices.
 

Are you asking for ICs for creating the 160Vdc bus, or for just controlling the LED strings? Do you need independent brightness control of multiple strings?
 

...just controlling the led strings.

.....i dont need brightness control.
 

CD4017, driving 10 small Fet's can provide 10 channels of 1/10 duty cycle and costant current on DC bus as required. Fet's, dont need to be of high voltage. If led is of 3.6V then 3.6x40=144V. For remaining 160-144=16V drop, a series resistor can also do the job. Put fet in -ve side with a series resistor. Resister value will be 1/10 times less than normal. If DC bus is not constant and current need to be monitored, SG3525 with two Fet's can provide two channels. A resistor in ground loop can sense current.
 

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