High-Voltage, Linear High-Brightness LED

Driver with Open-LED Fault Detect

8 ______________________________________________________________________________________

drops below 30mV for 25µs. When the fault condition

is detected, the LED driver is turned off, and a 2.8mA

current source charges the capacitor between FLTS

During subsequent power cycles, if the voltage on FLTS

is greater than 1.65V due to the charge retained in the

FLTS capacitor, the LED driver is turned off. This pro-

vides an open-LED fault-protection feature that can be

disabled by connecting FLTS to ground. In a multistring

application (Figure 2), where all FLTS pins are connected

together, a fault detected on one channel causes other

channels to turn off as well. The retention capability on

the FLTS is dependent on the leakage current and the

value of the capacitor used. If the retention capability is

high, the fault condition could be retained or memorized

for a long period after the supply is turned off.

Thermal Protection

The MAX16839 enters thermal-shutdown mode in the

event of overheating. When the junction temperature

circuit turns off the series pass element. The MAX16839

recovers from thermal-shutdown mode when the junc-

assert during an overheating event.

12V

12V

UVLO

50mA

50mA

4Fs

2.5Fs

12V FLTS

LEDGOOD (INTERNAL)

t

t

t

t

t

t

CONNECT TO 5V

SUPPLY OR LEAVE

UNCONNECTED

DIM SIGNAL

DIM

DIM

FLTS

FLTS

FLTS SIGNAL

0.01FF

0.01FF

IN

SINK

SINK

CS

CS

GND

IN

GND

0.1FF

MAX16839

MAX16839