1. for LED fail (normal/rare short/ short)
To MCU
Current Sense
for LED fail (normal/rare short/ short)
Clamp Diode
For overvoltage
In case LED is Open
Vin=48V ( Or 24V)
EN/UV
VIN
GATE1
CSP1
CSN1
BOOT1
VCC1
VLED1
Rsense1
Rsense2
Rsense3
White LED
CH1 Only
IF=700mA
IF=1000mA
IF=1050mA
CH1+CH2
IF=350mA each
IF=500mA each
IF=525mA each
CBOOT
CVCC
IF(Rsense)
selection
To MCU
Overvoltage protection
for LED is Open

2. Hello
My customer had chosen TPS92518 for 2019 LED light, and the key feature is 0.1% dimming ratio.
So, customer think [LEDx_PKTH_DAC] = 255 (the maximum value) for accuracy because
we see description * in the data sheet p44. *
" For the highest current set-point, set the peak threshold register to be as high
as possible. Use [LEDx_PKTH_DAC] = 255 (the maximum value) if possible to increase the converter
accuracy."
On the other hand , they want change LED current 3 case in the same PCB.
Attached ppt is block diagram . Q1
We don't know the relationship [LEDx_PKTH_DAC] = 255 (the maximum value) and accuracy for 0.1% dimming ration well.
Do you suggest to use [LEDx_PKTH_DAC] = 255 (fixed) for 0.1% ratio ? ( Off course it should depends on PWM pulse resolution) Q2
If we fix [LEDx_PKTH_DAC] = 255, then we should change IF( Rsense resistor) using switch ..( Pls refer to ppt)
Do you think this is okay in practical?
Would you please have any idea to change IF value with 0.1% dimming ratio? Q3
Vin varies 48V and 24V in case by case .
External components and resistor setting may be same for different Vin if frequency may be different?
If Vin were changed, switching frequency should be changed for same TOFF, but
not necessary to change inductor and register setting... right?
But UVLO setting should be changed in d/s Fig 31. Q4
Would you please have your opinion about Over Current protection for LED short, Over voltage protection for LED Open
and also IF( Rsense) changing about attached ppt kindly ?