The LTC3600 is a high efficiency, monolithic synchronous buck regulator whose output is programmed with just one external resistor. The accurate internally generated 50μA current source on the ISETpin allows the use of a single external resistor to program an output voltage that ranges from 0V to 0.5V below VIN. The VOUTvoltage feeds directly back to the error amplifier in unity gain fashion and equals the ISETvoltage. The operating supply voltage range is 4V to 15V, making it suitable for dual lithium-ion battery and 5V or 12V input point-of-load power supply applications.The operating frequency is synchronizable to an external clock or programmable from 200kHz to 4MHz with an external resistor. High switching frequency allows the use of small surface mount inductors. The unique constant on-time architecture is ideal for operating at high frequency in high step-down ratio applications that also demand fast load transient response.ApplicationsVoltage Tracking SuppliesPoint-of-Load Power SuppliesPortable InstrumentsDistributed Power Systems