中等尺寸LCD屏LED背光驱动芯片 PT4110 PDF文档下载

http://www.micro-bridge.com/data/CRpowtech/PT4110应用说明.pdf

DC-DC电感式升压驱动器

*  输入电压范围为2.7－5.5V，最大输入电流1.2A

*  最大输出35V，可驱动多并多串32颗以上20mA的LED

 特点：

*  抖频技术减小EMI

*  300mV的反馈电压提高效率

*   1.2 MHz的开关频率，减小电感值为10uH

*  每个周期的限流保护、过压保护、欠压锁定、软启动

应用：

*  数码相框、移动DVD、GPS和所有中等尺寸屏的背光驱动

The PT4110 is a high efficiency step-up DC/DC converter designed for driving multiple strings of up to six series-connected white LED from a single cell Lithium Ion battery. It regulates the output current, ideal for driving light emitting diodes (LED) whose light intensity is proportional to the current passing through them. The external ballast resistor sets the LED current ranging from 5mA to 20mA, which can be easily adjusted using either a DC voltage or a pulse width modulated (PWM) signal alternatively. Its low 300mV feedback voltage reduces power loss and improves efficiency.

The PT4110 has multiple features to protect itself from fault conditions including built-in over voltage protection, cycle-by-cycle current limit, over temperature shutdown, input under voltage control and integrated soft-start.

¨          2.7V to 5.5V Input Voltage Range

¨          35V Maximum Step-Up Voltage

¨          <1µA Shutdown Mode

¨          1.2MHz Fixed Frequency Operation

¨          Cycle-By-Cycle Current Limit

¨          Over Voltage Protection

¨          Under Voltage Lockout

¨          Integrated Soft-Start

¨          Thermal Shutdown

¨          Frequency Jittering for better EMI performance

¨          White LED Power Suppliers

¨          Flat Screen LCD Bias Suppliers

¨          Portable Media Players

¨          GPSs