Hi,
I'm designing a circuit to control chains of 3 LEDs (3 LEDs in series). I'm planning to use the CAT4016 constant current driver (data sheet here).
My voltage source for the LEDs is 8.2V, each LED has a 2.4V drop at 50mA, so the voltage presented to each sink pin is 1V (8.2 - 2.4*3). I've attached a diagram of this setup (one circuit shown for simplicity).
The sink pins are 5.5V tolerant. There are other ICs which have higher voltage tolerances on the sink pins. I don't understand why that would be needed. Hence wanted to ask if there is reason for this? And more importantly, I wanted to check if my circuit reasoning is sound (i.e. if there are any conditions, such as startup inrush, where 8.2V might be applied to the sink pins).
Many thanks.
I'm designing a circuit to control chains of 3 LEDs (3 LEDs in series). I'm planning to use the CAT4016 constant current driver (data sheet here).
My voltage source for the LEDs is 8.2V, each LED has a 2.4V drop at 50mA, so the voltage presented to each sink pin is 1V (8.2 - 2.4*3). I've attached a diagram of this setup (one circuit shown for simplicity).
The sink pins are 5.5V tolerant. There are other ICs which have higher voltage tolerances on the sink pins. I don't understand why that would be needed. Hence wanted to ask if there is reason for this? And more importantly, I wanted to check if my circuit reasoning is sound (i.e. if there are any conditions, such as startup inrush, where 8.2V might be applied to the sink pins).
Many thanks.
Attachments
-
46.3 KB Views: 29