The LTC3541-3 combines a synchronous buck DC/DC converter with a very low dropout linear regulator (VLDO™regulator) and internal feedback resistor networks to provide two output voltages from a single input voltage with minimum external components. When configured for dual output operation, the LTC3541-3’s auto start-up feature will bring the 1.575V VLDO/linear regulator output into regulation in a controlled manner prior to enabling the 1.8V buck output without the need for external pin control. The 300mA VLDO/linear regulator output will source only 30mA until the buck output achieves regulation. The input voltage range is ideally suited for applications powered from a Li-Ion battery and 5V or 3.3V rails. The synchronous buck converter provides a high efficiency output, typically 90%. It can provide up to 500mA of output current while switching at 2.25MHz, allowing the use of small surface mount inductors and capacitors. A mode select pin allows Burst Mode operation to be enabled for higher efficiency at light load currents, or disabled for lower noise, constant frequency operation. The VLDO regulator provides a low noise, low voltage output capable of providing up to 300mA of output current using only a 2.2μF ceramic capacitor. The input supply voltage of the VLDO regulator (LVIN) may come from the buck regulator or a separate supply. Options Vout Switcher (V) Vout VLDO LTC3541 Adj. down to 0.8V Adj. down to 0.4V LTC3541-1 Adj. down to 0.8V Adj down to 0.4V LTC3541-2 1.875V fixed 1.5V fixed LTC3541-3 1.8V fixed 1.575 fixed Applications * Digital Cameras * Cellular Phones * PC Cards * Wireless and DSL Modems * Other Portable Power Systems * High Efficiency 500mA Buck Plus 300mA VLDO Regulator * Auto Start-Up Powers VLDO/Linear Regulator Output Prior to Buck Output * Independent 500mA High Efficiency Buck (VIN: 2.7V to 5.5V) * 300mA VLDO Regulator with 30mA Standalone Mode * No External Schottky Diodes Required * Fixed Buck Output Voltage: 1.8V * VLDO Input Voltage Range (LVIN: 1.675V to 5.5V) https://elecena.pl/product/258416/high-efficiency-buck-vldo-regulator 2007-03-04 https://elecena.pl/product/258416/high-efficiency-buck-vldo-regulator 2014-06-11 https://elecena.pl/product/258416/high-efficiency-buck-vldo-regulator 2025-01-18