Synchronous Boost Converters Operate From Low Voltages

Optimized to operate from low input voltages such as those provided from a single- or dual-cell battery, the UCC39411/2/3 family of low-power synchronous boost converters are well-suited for use in applications such as pagers, PDAs, cell phones and portable instruments. They also provide a wide input range that can accommodate such diverse power sources as alkaline, NiCd, NiMH, and lithium-ion batteries. UC39411 provides a user-programmable output voltage, while UCC39412 offers a fixed 3.3V output and UCC39413 a fixed 5V output. Other features of the converters include an auxiliary output and a user-programmable power on reset function. The ICs guarantee 1V startup under full load with operation down to an input voltage of 0.5V. Variable frequency allows for reported converter efficiencies greater than 90%. A low-power shutdown mode allows for full output disconnect, while the IC draws only 3 µA shutdown supply current.