TPS61169DCKR

TPS61169是一款升压转换器，配有额定电压为40V的集成开关场效应晶体管(FET)，可驱动LED串。该升压转换器内部具有一个40V、1.8A金属氧化物半导体场效应晶体管(MOSFET)，电流下限为1.2A，可针对小型或大型面板背光照明驱动单个LED或LED串。默认的白色LED电流通过外部传感器电阻RSET设定，反馈电压稳压至204mV。运行期间，LED电流可通过施加到CTRL引脚上的脉宽调制(PWM)信号加以控制，该信号的占空比决定反馈基准电压。TPS61169不会突发LED电流，因此不会在输出电容器上产生可闻噪声。为提供最佳保护，该器件集成了LED开路保护特性，该特性会在LED开路状态下禁用TPS61169，以防止输出电压超过IC最大绝对额定电压。TPS61169采用节省空间的5引脚SC70封装。

The TPS61169 is a high-efficiency, high-output voltage boost converter in small package size. The device integrates 40-V/1.8-A switch FET and is designed for output voltage up to 39 V with a switch peak current limit of 1.2 A minimum. Its large driving capability can drive single or parallel LED strings for small to large size panel backlighting.

The TPS61169 operates in a current mode scheme with quasi-constant frequency. It is internally compensated for maximum flexibility and stability. The switching frequency is 1.2 MHz, and the minimum input voltage is 2.7 V. During the on-time, the current rises into the inductor. When the current reaches a threshold value set by the internal GM amplifier, the power switch MOSFET is turned off. The polarity of the inductor changes and forward biases the schottky diode which lets the current flow towards the output of the boost converter. The off-time is fixed for a certain VIN and VOUT, and therefore maintains the same frequency when varying these parameters.

However, for different output loads, the frequency slightly changes due to the voltage drop across the RDS(ON) of the power switch MOSFET, this has an effect on the voltage across the inductor and thus on tan (tOFF remains fixed). The fixed off-time maintains a quasi-fixed frequency that provides better stability for the system over a wider range of input and output voltages than conventional boost converters. The TPS61169 topology has also the benefits of providing very good load and line regulations, and excellent line and load transient responses.

The feedback loop regulates the FB pin to a low reference voltage (204 mV typical), reducing the power dissipation in the current sense resistor.

• 2.7V至5.5V输入电压
• 集成40V、1.8A金属氧化物半导体场效应晶体管(MOSFET)
• 高达38V的LED串驱动电压
• 1.2A开关电流下限
• 1.2MHz开关频率
• 204mV基准电压
• 内部补偿
• PWM亮度控制
• LED开路保护
• 欠压保护
• 内置软启动
• 热关断
• 效率高达90%

• 智能手机背光照明
• 平板电脑背光照明
• PDA、掌上电脑、GPS接收器
• 便携式媒体播放器，便携式电视
• 针对小尺寸媒体播放器的白色LED背光照明