Produktbeskrivning
3.3V/5V Step-Up DC-DC Converters
The MAX856 is a high-efficiency, CMOS, stepup, DC-DC switching regulator for small, low input voltage or battery-powered systems. The MAX856 accepts a positive input voltage between 0.8V and VOUT and converts it to a higher, pin-selectable output voltage of 3.3V or 5V. Typical efficiencies are greater than 85%. Typical quiescent supply current is 25uA (1uA in shutdown). The MAX856 combines 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 has a 500mA peak inductor current limit.
Features
* 0.8V to VOUT Input Supply Voltage
* 0.8V Typ Start-Up Supply Voltage
* 85% Efficiency at 100mA
* 25uA Quiescent Current
* 1uA 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)
Applications
* 3.3V to 5V Step-Up Conversion
* Palmtop Computers
* Portable Data-Collection Equipment
* Personal Data Communicators/Computers
* Medical Instrumentation
* 2-Cell & 3-Cell Battery-Operated Equipment
* Glucose Meters
The MAX856 is a high-efficiency, CMOS, stepup, DC-DC switching regulator for small, low input voltage or battery-powered systems. The MAX856 accepts a positive input voltage between 0.8V and VOUT and converts it to a higher, pin-selectable output voltage of 3.3V or 5V. Typical efficiencies are greater than 85%. Typical quiescent supply current is 25uA (1uA in shutdown). The MAX856 combines 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 has a 500mA peak inductor current limit.
Features
* 0.8V to VOUT Input Supply Voltage
* 0.8V Typ Start-Up Supply Voltage
* 85% Efficiency at 100mA
* 25uA Quiescent Current
* 1uA 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)
Applications
* 3.3V to 5V Step-Up Conversion
* Palmtop Computers
* Portable Data-Collection Equipment
* Personal Data Communicators/Computers
* Medical Instrumentation
* 2-Cell & 3-Cell Battery-Operated Equipment
* Glucose Meters