If I have a string of 4 series LED and 1 series resistor.
That resistor will set the current. Let's say it sets the current for that path at 20mA.
So if I measure current at the cathode of the last LED, it will 20mA. If I measure current at any point, it should be 20mA
If I look at the luminosity vs current graph of an LED, it gets brighter as forward current increases.
Can I use 20mA to determine its brightness or do I need to divide by 4 (4 series led) to get a value of 5mA to determine brightness?
And why would I not need to divide by 4. Is it because I need more voltage to power an additional led which means 20mA at either 2, 4, 6, or 8v which is more power at each step?
So for an LED driver like : IS31FL3746A-QFLS4-TR
https://www.digikey.com/en/products/detail/lumissil-microsystems/IS31FL3746A-QFLS4-TR/9759696
If each current sink pin can only handle 34mA but I can put 11 led on each current sink pin, does that mean each LED can get the full 34mA?
I want to drive 126 white LED and this seems like a great driver.
On page 5 it says for I_LED: "Average current on each LED: 3.03mA" while I_OUT:"Maximum constant current of CS_y: 34.5mA"
Help me understand that.
Thank you for your time.
That resistor will set the current. Let's say it sets the current for that path at 20mA.
So if I measure current at the cathode of the last LED, it will 20mA. If I measure current at any point, it should be 20mA
If I look at the luminosity vs current graph of an LED, it gets brighter as forward current increases.
Can I use 20mA to determine its brightness or do I need to divide by 4 (4 series led) to get a value of 5mA to determine brightness?
And why would I not need to divide by 4. Is it because I need more voltage to power an additional led which means 20mA at either 2, 4, 6, or 8v which is more power at each step?
So for an LED driver like : IS31FL3746A-QFLS4-TR
https://www.digikey.com/en/products/detail/lumissil-microsystems/IS31FL3746A-QFLS4-TR/9759696
If each current sink pin can only handle 34mA but I can put 11 led on each current sink pin, does that mean each LED can get the full 34mA?
I want to drive 126 white LED and this seems like a great driver.
On page 5 it says for I_LED: "Average current on each LED: 3.03mA" while I_OUT:"Maximum constant current of CS_y: 34.5mA"
Help me understand that.
Thank you for your time.