ADP1878 Datasheet | Analog Devices

Data Sheet Synchronous Buck Controller with Constant On Time and Valley Current Mode ADP1878/ADP1879 Features Power input voltage range: 2.95 V to 20 V On-board bias regulator Minimum output voltage: 0.6 V 0.6 V reference voltage with ±1.0% accuracy Supports all N-channel MOSFET power stages Available in 300 k Hz, 600 k Hz, and 1.0 MHz options No current sense resistor required Power saving mode (PSM) for light loads (ADP1879 only) Resistor programmable current limit Power good with internal pull-up resistor Externally programmable soft start Thermal overload protection Short-circuit protection Standalone precision enable input Integrated bootstrap diode for high-side drive Starts into a precharged output Available in a 14-lead LFCSP_WD package APPLICATIONS Telemunications and networking systems Mid-to-high end servers Set-top boxes DSP core power supplies GENERAL DESCRIPTION The ADP1878/ADP1879 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. These devices offer optimum performance at low duty cycles by using a valley, current-mode control architecture allowing the ADP1878/ADP1879 to drive all N-channel power stages to regulate output voltages to as low as 0.6 V. The ADP1879 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 ADP1879 Power Saving Mode (PSM) section for more information). Available in three frequency options (300 k Hz, 600 k Hz, and 1.0 MHz) plus the PSM option, the ADP1878/ADP1879 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). In addition, soft start...