Silan launched white LED with PWM dimming driver chip

Hangzhou Silan microelectronics company recently released three with PWM dimming function of high-power white LED driver chip -- SB42511, SB42520 and SB42821. The three chip input voltage from 6V to 25V, the output current is up to 1A; the built-in temperature protection circuit, over-current protection circuit and PWM dimming circuit system; high conversion efficiency, efficiency in series with multiple LED can reach more than 95%; the chip can be PWM dimming, output current through the external PWM signal adjustment LED, in the 100Hz ~ 2kHz range can achieve the dimming effect is good; in addition, SB42511, bootstrap circuit control method using the unique SB42520 chip, no external Schottky, in series with a plurality of LED can also start this, compared with other similar products bootstrap mode the performance has been greatly improved.

From the current characteristics, the control system of SB42511 and SB42520 using a dual loop current control method, the chip regardless of changes in the input voltage, or to drive LED the number of changes, have shown good ability to adjust the current, output current change rate control within plus or minus 1%, the obvious improvement in performance on. SB42821 uses the constant turn off control technology, does not need to carry on the loop compensation, needs the peripheral components to be few. In addition, SB42821 and SB42520 are also integrated within the enable function, in the off state, the quiescent current is only 25 A.

This series of chips are made of lead-free small size packaging, green environmental protection, internal power consumption is small, more conducive to the use of users.

Source: International Electronic Business