The realization of the white light LED controller scheme without inductance charging

ANPEC Electronics (Anpec) launched the white LED controller power management solutions: APW7003, APW7008, APW7071 and APW7005, has the advantages of small volume, low calorific value, low power consumption, long service life, fast response, environmental protection and easy to develop into a short thin flat package products etc.. APW7003 and APW7008 for the non inductive charging pump IC, not only the required external components are very small, can save the application circuit volume, and no inductance EMI interference problem, the use of a very simple and convenient. The stable output voltage of 5V APW7003 can provide an output current of 100mA, applications can meet 5 parallel white LED (each 20mA), and to allow a brightness signal to adjust the PWM of LED; APW7008 is a white LED 4 channel driver IC, through 3 logic control pin. Changes can allow a variety of LED switch combination, each channel can provide high accuracy and high degree of LED, current, brightness and allow the signal to adjust to a PWM LED. APW7008 can detect the input voltage changes, automatic operation in 1X, 1.5x and 2x charging mode, when the IC operation in the 1x mode efficiency can be as high as 80% to 90%. APW7003 and APW7008 in the protection function is complete, including thermal shutdown, overvoltage protection, output short circuit protection (APW7008) and soft boot activation function, in addition to the two IC are provided in standby mode, enter standby mode when the static operating current can be lower than 1uA. APW7003 package for the SOT-23-6 lead-free package, APW7008 is QFN-163 x 3 lead-free package, both of the input voltage range can meet the general single lithium battery applications. APW7005 (high current 950) and APW7071 (small current 400) operating frequency up to 1MHz, the output is only a 0.1uF capacitor, so that the external components to minimize the performance. The operation between 2.5V to 6V input voltage range, suitable for use in a single lithium battery powered, 4 series of white LED single lithium battery can drive, built-in 18V overvoltage protection function, which can avoid the load contact with air and unexpected pressure. The use of PFM control architecture, light load efficiency can reach 85% (Vin=3.5V, Loading=1mA, Vout=12V), the maximum efficiency can be as high as 87%. 0.25V provides internal reference voltage as LED limiting can get the highest efficiency, and prolonging the service life of the battery, the built-in APW7005/APW7071 limit current of 900mA/400mA, both the use of SOT-23-6 package are of great help to save board space.

Source: China switch network