描述 Description

The LX1741 is a compact high efficiency step-up boost controller. Featuring a pseudo-hysteretic pulse frequency modulation topology, the LX1741 was designed for maximum efficiency, reduced board size, and minimal cost.Utilizing an external N-Channel MOSFET, the LX1741 offers designers maximum flexibility with respect to efficiency and cost. The LX1741 provides several design enhancements that improve overall performance under very light load currents by implementing control circuitry that is optimized for portable systems - thus providing a quiescent supply current of only 80μA (typ) and a shutdown current of less than 1μA.The input voltage ranges from 1.6V to 6.0V, allowing for a wide selection of system battery voltages. Start-up operation is guaranteed at 1.6V input. The output voltage is programmed easily using two external resistors in conjunction with the feedback pin. Depending on the MOSFET selected, the LX1741 is capable of achieving output voltages much higher than 40V.The LX1741 has an additional feature for simple dynamic adjustment of the output voltage (i.e., up to ±15% of the nominal output voltage). Voltage adjustment is achieved via an analog reference signal or a direct PWM input signal applied to the ADJ pin. Any PWM amplitude is easily accommodated with a single external resistor.The LX1741 is available in both the 8-Pin MSOP, and the miniature 8-Pin MLP requiring minimal PCB area.Key Features:> 90% Maximum Efficiency80μA Typical Quiescent Supply CurrentExternally Programmable Peak Inductor Current Limit For Maximum EfficiencyLogic Controlled Shutdown< 1μA Shutdown CurrentDynamic Output Voltage Adjustment Via Analog Reference Or Direct PWM Input8-Pin MSOP Package or 8-Pin MLP Part??ROHS, PB Free