19-0211; Rev 4; 5/96
NUAL KIT MA ATION SHEET A EVALU T A D WS FOLLO
3.3V/5V or Adjustable-Output, Step-Up DC-DC Conver...
19-0211; Rev 4; 5/96
NUAL KIT MA ATION SHEET A EVALU T A D WS FOLLO
3.3V/5V or Adjustable-Output, Step-Up DC-DC Converters
____________________________Features
o o o o o o o o o o 0.8V to 6.0V Input Supply
Voltage 0.8V Typ Start-Up Supply
Voltage 85% Efficiency at 100mA 25µA Quiescent Current 1µA Shutdown Mode 125mA and 500mA Switch-Current Limits Permit Use of Low-Cost Inductors Up to 500kHz Switching Frequency ±1.5% Reference Tolerance Over Temperature Low-Battery Detector (LBI/LBO) 8-Pin SO and µMAX Packages
_______________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 inductors. The MAX856/MAX857 have a 500mA peak inductor current limit. The MAX858/MAX859 have a 125mA peak inductor curren...