TL4242: TL4242 in parallel

Hi Franz.

Could you tell me some detail about the customer's project:

1)Customer‘s application, auto or non-auto?

2)LED's connection type: one LED a string or n LED a string?how many strings are in parallel

3) LED’s parameter: if vf

4)whether the customer have dimming requrie or not  

Two questions:

1) Can the TL4242 be connected in parallel (similar to Mosfets)?

a：no

2) Is there something similar with higher current and similar status output/PWM input?"

a：for one channel led driver, we recommend you to consider Tps92613-q

http://www.ti.com/lit/ds/symlink/tps92613-q1.pdf

Hi Frank,

thanks for the quick response...

I'm the customer, some answers:

1) non-auto, standard industrial

2,3) two types of LEDs: 500mA@7V  and 200mA@6.5V;  5 LEDs in series on one board; 6 boards are in one string, each connected to a 36V..38V supply bus and a PWM and ST line; 7 strings at all. The board is a standard alu-core PCB, thermal good but bad for layouting (only one layer). PWM dimmimg is neccessary to compensate aging, ST is checked by a current source, the voltage  over the ST-line gives the position of the bad board.

One TL4242 is perfect for the 200mA-LEDs; the 500mA LEDs are critical. The idea is to parallel the 500mA into two linear drivers with a current sharing ratio of at least 1:2. But this is the point, how to guarantee this (some sync-resistors with a voltage drop of 0.5 … 1V are possible).

The TPS92613 is worth to check...

Thanks

Frank

Hi 

I have reviewed the solution that parallel 2 TL4242, we think it wrong to use as that.Becasue TL4242 have a ref pin which connect a shunt resisor to set the output current.if you connet to 4242 in parallel there will be wrong in close-loop. So if you want to drive the 500mA LED, we recommend you to use TPS92613.