Semiconductor launches new white LED driver

National Semiconductor Corporation Ns (National Semiconductor Corporation) (New York stock exchange code: NSM) announced the launch of a full-featured low noise white light emitting diode driver, provide stable drive current for the main screen wireless mobile phone and other portable electronic products and small keyboard.

This model driver chip LM3570 can output three stable current, total drive current up to 80mA, enough to drive the main screen in one to three white LEDs and a small keyboard and a greater number of the other light emitting diode. LM3570 chip with 3/2 times the high efficiency boost function, help to extend the battery life, and because of the higher efficiency, so can reduce the system to power supply requirements. Application of LM3570 chip is very wide, the most is applicable to portable electronic products with white or blue light emitting diode main screen or keypad backlighting or surface light, also applies to the use of a lithium battery of the electronic devices such as personal digital assistants, notebook computer and mobile phone. The input voltage range of LM3570 driver chip is 2.7V to 5.5V; the output voltage of 4.35V; a high effective pulse width modulation (PWM) control pin; shutdown current does not exceed 1mA; switching frequency (typ) is 500kHz; the operating temperature range is -40 to 85 DEG C.

Features: input voltage output voltage range of 2.7V to 5.5V stable (Vout = 4.35V) IDx stable output current, the current match each other, accuracy of + 0.3% 3/2 times high efficiency boost function can drive 1, 2 or 3 white LEDs, but does not produce partial pressure resistance loss by voltage when the light emitting diode total output current can drive the auxiliary keyboard up to 80mA with high effective function with high level allows the pulse width modulation (PWM) control pin, can ensure the independent control of the current output volume of different switching frequency is very small shutdown current does not exceed 1mA 500kHz (typ) linear regulator function to ensure that LM3570 wide temperature range of the noise in a predictable range at -40 DEG C to 85 DEG C with no The 14 pin LLP package of the extended pin is purchased in the order of $1000 for each unit, with a price of $1.40 per unit.