MAX857

19-0211; Rev 4; 5/96 EVFAOLLULAOTWIOSNDKAITTAMSAHNEUEATL 3.3V/5V or Adjustable-Output, Step-Up DC-DC Converters MAX856–MAX859 _______________General Description The MAX856–MAX859 are high-efficiency, CMOS, stepup, DC-DC switching regulators for small, low input voltage or battery-powered systems. The MAX856/MAX858 accept a positive input voltage between 0.8V and VOUT and convert it to a higher, pin-selectable output voltage of 3.3V or 5V. The MAX857/MAX859 adjustable versions accept 0.8V to 6.0V input voltages and generate higher adjustable output voltages in the 2.7V to 6.0V range. Typical efficiencies are greater than 85%. Typical quiescent supply current is 25µA (1µA in shutdown). The MAX856–MAX859 combine ultra-low quiescent supply current and high efficiency to give maximum battery life. An internal MOSFET power transistor permits high switching frequencies. This benefit, combined with internally set peak inductor current limits, permits the use of small, low-cost induc...