OB3375x

GENERAL DESCRIPTION

The OB3375X is a high efficiency LED power switch designed for white LEDS and for large LCDS backlight. OB3375X is built-in a quasi-resonant control method buck DC/DC converter. The controller implements a peak current mode control scheme and an internal transconductance amplifier to accurately control the output current over a wide input and load conditions. The transconductance amplifier reference is set by internal reference voltage and the duty cycle at HPWM pin. Low frequency LPWM dimming input that can accept an external control signal with a duty ratio of 1%-100%.

OB3375X offers comprehensive protection features to protect the system in various fault conditions such as Diode & Inductor short protection, CS open protection, Drain/CS short protection, LED+/LED- short protection, LED-/GND short circuit protection, LED open loop protection, Over temperature protection (OTP). The cycle-by-cycle current limit function limits the maximum current flowing through the internal MOSFET.

OB3375X is offered in SOP8 package.

 

FEATURES

n Low system cost and high efficiency

n Quasi-Resonant buck topology operation

n Programmable CC regulation

n PWM and PWM to analog combination dimming

n Zero voltage signal detected to improve efficiency and EMI performance

n LED+/LED- short circuit protection

n LED-/GND short circuit protection

n LED open loop protection

n Cycle-by-cycle current limiting

n Built-in leading edge blanking (LEB)

n VIN under voltage lockout with hysteresis

n Over temperature protection (OTP)

n Diode & Inductor short protection

n Drain/CS short protection

n CS open protection

n Low standby current

 

APPLICATIONS

n LED backlight

 

 

TYPICAL APPLICATION