OB3356 is a high performance current balance controller optimized for large size LED backlighting application. It integrates 6 channels of current balancer, and provides a high performance and high reliability LED backlighting solution using NPN bipolar transistor.
Each channel the current in is set by an external resistor connected between the emitter of the NPN bipolar transistor and ground. High precision current matching is achieved among the LED strings. OB3356 provides base current up to 20mA per channel, such that it can drive cost effective lower NPN bipolar power transistor.
OB3356 supports external PWM dimming and analog dimming that allow flexible control of the backlight luminance. The LED current is directly modulated by external PWM signal when PWM dimming mode is selected. The LED current can be adjusted by an external DC voltage when analog dimming mode is selected.
OB3356 offers comprehensive fault protection such as over current protection (OCP) in each channel, output over voltage protection (OVP), IC power supply under voltage lockout (UVLO), and LED open & short protection. An independent fault flag logic will be outputted and latch shut down when a fault occurs.
■ 6-channel current balance controller
■ Base current up to 20mA per channel
■ Analog dimming mode & External PWM dimming mode
■ Very low standby current (typical 5uA)
■ Comprehensive protections coverage covers LED short / open protection, OVP, OTP, OCP, UVLO
■ Voltage feedback control to external SMPS
■ LCD Monitor
■ LCD TV
■ Flat panel display