深圳市四海恒通科技有限公司 （非本站正式会员）

The AX2021 is a continuous conduction mode inductive step-down converter, designed for driving single or multiple series connected LED efficiently from a voltage source higher than the total LED chain voltage. The device operates from an input supply between 8V and 32V and provides an externally adjustable output current of up to 0.45A. Depending upon the supply voltage and external components, the AX2021 can provide more than 15 watts of output power. The AX2021 includes the power switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current, and a dedicated DIM input accepts a wide range of pulsed dimming. Applying a voltage of 0.3V or

lower to the DIM pin turns the output off and switches the device into a low current standby state.

       The AX2021 is available in TSOT23-5L package.

AX2021特点：

n  极少的外部元器件

n  输入电压范围：8V-32V

n  最大输出电流 0.45A

n  Single pin on/off and brightness control using PWM

n  最高开关频率1MHz

n  恒流精度5%

n  高侧的输出电流传感电路

n  Hysteretic Control: No Compensation

n  可调恒定的LED电流