United States NS launched high current flash LED driver

In March 31, 2008, National Semiconductor Corporation Ns (National Semiconductor Corp., NS) launched a high current LED flash drive, two LED can drive a portable multimedia device camera flash. This model LM3553 driver belongs to the national semiconductor PowerWise high efficiency chip series, can drive the portable equipment for one of the two high current series LED, for example, mobile phone, PDA, smart phones, portable medical scanners and strobe lights etc..

LM3553 flash LED driver is a fixed frequency boost DC / DC converter, built-in two stable current receiver, just a lithium battery can output up to 1.2A of load current. The two series high current LED can be driven by an adjustable overvoltage protection circuit to obtain the maximum brightness / power ratio. LM3553 enables the camera to have a high power flash mode to shoot still life, and low power torch mode to shoot video clips. In order to expand the scope of application, the designer through the I2C compatible interface, so that the product has 128 flash current level and 16 flash timing. In addition, the LM3553 also has a built-in pause protection system to prevent flash LED from being damaged in the wrong operation.

LM3553 LED flash drive national semiconductor can make low power system enhance the light output to the highest value reached 90%, or even higher, so it is included in the national semiconductor PowerWise high efficiency chip series.

Technical features of LM3553 LED driver

1 through a small inductor with low saturation current, the switching current limit can be adjusted. 2 voltage mode for LED backlight or audio amplifier provides voltage 5V. 3 through the internal registers or FEN and TX pins, the flash can be operated in high power or low power torch mode, driving one or more high current LED. 4.TX input can be forced to change the flash mode to a low current torch mode, so that the flash pulse can be achieved with amplifier power amplifier (RF power) application or other high current mode of operation. 5 GPIO pins provide hardware support for the system. 6 if the system fails, the hardware reset pin provides full control of the device. 7 built in soft start function to avoid the start and fast switching frequency when a large number of inrush current, allowing the design of the product with a smaller external components.

LM3553 uses LLP package 12 pin. The product is purchased for 1000 units, single price of $1.20, has been able to bulk supply.

Source: China Semiconductor Lighting Network