Linear Technologies' LTC3609 is a high efficiency, synchronous buck regulator that can deliver up to 6A of continuous output current at voltages as low as 0.6V. It operates from an input voltage range of 4V to 32V (36V ABS Max), making it ideal for applications with multi-cell Li-Ion, lead acid batteries or fixed input voltage rails up to 32V. Its valley current control architecture delivers very low duty cycle operation at high frequencies with excellent transient response. The operating frequency is set by an external resistor. With a switching frequency of up to 1MHz, the LTC3609 can utilize small, low cost ceramic capacitors and low profile inductors.
The LTC3609 uses internal switches with an RDS(ON) of only 18mOhms and 13mOhms to deliver efficiencies as high as 95%. It can also be configured for discontinuous or forced continuous operation. Forced continuous operation reduces noise and RF interference while discontinuous mode provides high efficiency by reducing switching losses at light loads, requiring only 900uA of quiescent current. Shutdown quiescent current is only 15uA. Additional features include a Power Good voltage monitor, adjustable current limit, output overvoltage protection and programmable soft-start.
The LTC3609EWKG is available from stock in a 52-lead, 7mm x 8mm QFN package. Pricing starts at $7.75 each in 1,000-piece quantities. An industrial grade version, the LTC3609IWKG, is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and is priced at $9.12 each in 1,000-piece quantities. All versions are available from stock.