Driving long LED strings from a 160VDC Bus

[grizedale]

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.

 

[atripathi]

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.

 

[mtwieg]

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?

 

[grizedale]

...just controlling the led strings.

.....i dont need brightness control.

 

[ALERTLINKS]

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.