Linear Launches 18V Synchronous Step-Down Regulator

The LTC3608 is a synchronous buck regulator that can deliver up to 8A of continuous output current at voltages as low as 0.6V. It operates from an input voltage range of 4V to 18V (20V ABS Max), making it ideal for applications with multicell Li-Ion, lead acid batteries or fixed voltage rails up to 15V. 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. Switching frequencies of up to 1MHz allow the utilization of small, low cost ceramic capacitors and low profile inductors. The LTC3608 uses internal switches with an RDS(ON) of only 10mOhms and 8mOhms to deliver efficiencies as high as 95%. The LTC3608 can 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. Shut down quiescent current is only 15uA. Additional features include a Power Good voltage monitor, adjustable current limit, output overvoltage protection and programmable soft-start. The LTC3608EWKG is available from stock in a 52-lead, 7mm x 8mm QFN package. Pricing starts at $7.50 in 1,000-piece quantities. An industrial grade version, the LTC3608IWKG is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and is priced at $8.63 in 1,000-piece quantities. All versions are available from stock.