Half the country launched LM3445 LED driver supports three end triac dimming

National Semiconductor Corporation Ns (National Semiconductor Corporation, NS) announced the introduction of a new off line constant current controller. The advantages of the product can support with three terminal bidirectional thyristor (TRIAC) forward or reverse phase control function of the traditional wall type light regulator, thereby stabilizing control of high brightness LED light dark, ensure that there is no light flicker problem. This supports the three end triac dimming control function of the LM3445 LED drive can not only support up to 100:1 dimming ratio, but also the constant current to drive the output string LED more than 1A, can be widely used in residential, commercial and industrial buildings, special lighting field.

Can support three end triac dimming function LM3445 LED driver can greatly improve the light output system, in a typical application case in accordance with the "Energy Star" (ENERGY STAR) power standard, belonging to the United States National Semiconductor PowerWise high energy efficiency products series.

The 10 pin Mini SOIC package of the national semiconductor LM3445 chip is an adaptive fixed off time AC / DC Buck constant current controller. The utility model is characterized in that a three terminal bidirectional silicon controlled light modulation decoder is arranged, and the utility model can be used to carry out the LED dimming function of the dimming contrast with the standard three terminal bidirectional thyristor dimmer. In addition, the chip can be used to support high frequency operation of the framework, and can be used with a small volume of external passive components.

Another feature of the LM3445 chip is a built-in bleeder circuit. Whenever the line voltage drops to a lower level, the current will continue to flow, so that the three terminal triac can continue to operate normally. In addition, most of the time the passive power factor correction circuit chip can be in the period directly from the line interception current positive voltage constant for buck regulator, and ensure the lowest power consumption. The advantages of LM3445 chip include: overheating shutdown, current limiting and undervoltage lockout protection.

Prices and availability

LM3445 chip has been bulk supply, procurement to 1000 units, a single price of $1.75.