The LT8609S is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 1.7µA of non-switching quiescent current. The LT8609S can deliver 2A of continuous current with peak loads of 3A (<1sec) to support applications such as GSM transceivers which require high transient loads. Top and bottom power switches are included with all necessary circuitry to minimize the need for external components. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock, or spread spectrum modulation of switching frequencies for low EMI operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VINundervoltage lockout or to shut down the LT8609S reducing the input supply current to 1µA. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up while the PG flag signals when VOUTis within ±8.5% of the programmed output voltage as well as fault conditions. The LT8609S is available in a small 16-lead 3mm × 3mm LQFN package.APPLICATIONSGeneral Purpose Step DownLow EMI Step Down