The ADP1874/ADP1875 are versatile current mode， synchronous step-down controllers. They provide superior transient response， optimal stability， and current-limit protection by using a constant on-time， pseudo fixed frequency with a programmable current limit， current control scheme. In addition， these devices offer optimum performance at low duty cycles by using a valley， current mode control architecture. This allows the ADP1874/ADP1875 to drive all N-channel power stages to regulate output voltages to as low as 0.6 V. The ADP1875 is the power saving mode （PSM） version of the device and is capable of pulse skipping to maintain output regulation while achieving improved system efficiency at light loads （see the ADP1875 Power Saving Mode （PSM） section for more information）。 Available in three frequency options （300 kHz， 600 kHz， and 1.0 MHz， plus the PSM option）， the ADP1874/ADP1875 are well suited for a wide range of applications that require a single-input power supply range from 2.95 V to 20 V. Low voltage biasing is supplied via a 5 V internal low dropout regulator （LDO）.