DESCRIPTION
The GXX3939 is a steep-up converter designed for driving up to 39 white LEDs(13 strings of 3
LEDs each)from a 5V system rail. The GXX3939 uses a current mode,fixed frequency architecture
to regulate the LED current ,which is measured through an external current sense resistor. Its low
101mV feedback voltage reduces power loss and improves sfficiency. The OV pin monitors the
output voltage and turns off converter if an over-voltage condition is present due to an open circuit
condition.
The GXX3939 includes under-voltage lockout, current limiting and thermal overload protection
preventing damage in the event of output overload.
The GXX3939is available in small 6-pin Sot23 or 8-pin QFN (2mm*2mm) package.
FEATURES
z 2.5V to 6V Input Voltage Range
z On Board Power MOSFET
z Drives up to 39 White LEDs at 5V Input
z Up to 92% Efficiency
z Over 1MHz Fixed Switching Frequency
z Open Load Shutdown
z Low 104mV Feedback Voltage
z Soft-Start/PWM Dimming
z UVLO, Thermal Shutdown
z Internal 1.3A Current Limit
APPLICATIONS
z Cell Phones
z Handheld Computers and PDAs
z Digital Still Cameras
z Small LCD DisplaysDESCRIPTION
The GXX3939 is a steep-up converter designed for driving up to 39 white LEDs(13 strings of 3
LEDs each)from a 5V system rail. The GXX3939 uses a current mode,fixed frequency architecture
to regulate the LED current ,which is measured through an external current sense resistor. Its low
101mV feedback voltage reduces power loss and improves sfficiency. The OV pin monitors the
output voltage and turns off converter if an over-voltage condition is present due to an open circuit
condition.
The GXX3939 includes under-voltage lockout, current limiting and thermal overload protection
preventing damage in the event of output overload.
The GXX3939is available in small 6-pin Sot23 or 8-pin QFN (2mm*2mm) package.
FEATURES
z 2.5V to 6V Input Voltage Range
z On Board Power MOSFET
z Drives up to 39 White LEDs at 5V Input
z Up to 92% Efficiency
z Over 1MHz Fixed Switching Frequency
z Open Load Shutdown
z Low 104mV Feedback Voltage
z Soft-Start/PWM Dimming
z UVLO, Thermal Shutdown
z Internal 1.3A Current Limit
APPLICATIONS
z Cell Phones
z Handheld Computers and PDAs
z Digital Still Cameras
z Small LCD Displays