High-Voltage, Linear High-Brightness LED

Driver with Open-LED Fault Detect

8 ______________________________________________________________________________________

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

detected, a 2.8mA current source charges the capaci-

is less than 15V. 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 provides an open-LED

fault-protection feature that can be disabled by connect-

ing 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 depen-

dent 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

not 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