I have to illuminate one of 3 high-power LEDs in sequence (backyard stoplight project).
I was thinking I might be able to use a DRV8834 as both a current limiter and sequencer:
Would this work:
-Set the DRV8834 output current to the maximum current of the high power LEDs (1.4A, DRV8834 can supply 1.5A continuous)
-Connect LED1 to Coil A1-A2
-Connect LED2 to Coil A1-A2 in reverse
-Connect LED3 to Coil B1-B2
-Drive the 8834 in index mode, half step.
Pulling it out of sleep at the beginning of each sequence would start at a known state.
Half step mode, steps 1,3,5,7 seem to power the coils at full-on, full-off.
Its okay if two LEDs are powered briefly for steps 2,4,6,8 (or I may use nEnbl during these transitions).
(Or i may simply use enable/phase mode)
1)Is it safe to connect two LEDs head to head and have only one powered with that much current passing through one?
I know this is typical for tiny LEDs.
I assume the reverse voltage is usually the same as the forward voltage, even for high power LEDs? (I can verify with the specific LED)
2)Will the driver handle a high power LED?
The LED behaviour will be instantaneous in comparison to motor windings, so is there some chopping/hysteresis/? aspect that needs to be considered?
Thanks very much!