The LTC3541-1 combines a synchronous buck DC/ DC converter with a very low dropout linear regulator (VLDO) to provide up to two output voltages from a single input voltage with minimal external components. When configured for dual output operation, the LTC3541-1's auto start-up feature will bring the VLDO/linear regulator output into regulation in a controlled manner prior to enabling the Buck regulator output without the need for external pin control. Buck output prior to VLDO/linear regulator output sequencing may also be obtained via external pin control. The input voltage range is ideally suited for Li-Ion batterypowered applications, as well as powering sub-3.3V logic from 5V or 3.3V rails. The synchronous buck converter provides a high efficiency output, typically 90%, capable of providing up to 500mA of continuous 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 continuous 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. OptionsVout Switcher (V)Vout VLDOAuto Start Up Sequencing LTC3541 Adj down to 0.8V Adj down to 0.4V Switcher, then VLDO LTC3541-1 Adj down to 0.8V Adj down to 0.4V VLDO, then switcher LTC3541-2 1.875V fixed 1.5V fixed Switcher, then VLDO LTC3541-3 1.8V fixed 1.575 fixed VLDO, then switcher
