ADP1871

Data Sheet Synchronous Buck Controller with Constant On-Time and Valley Current Mode ADP1870/ADP1871 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 kHz, 600 kHz, and 1.0 MHz options No current-sense resistor required Power saving mode (PSM) for light loads (ADP1871 only) Resistor-programmable current-sense gain Thermal overload protection Short-circuit protection Precision enable input Integrated bootstrap diode for high-side drive Starts into a precharged load Small, 10-lead MSOP and LFCSP packages APPLICATIONS Telecom and networking systems Mid to high end servers Set-top boxes DSP core power supplies 12 V input POL supplies GENERAL DESCRIPTION The ADP1870/ADP1871 are versatile current-mode, synchronous step-down controllers that provide superior transient response, optimal stability, and current-limit protection by using a constant on-time, pseudo-fixed frequency with a programmable currentlimit, current-control scheme. In addition, these devices offer optimum performance at low duty cycles by utilizing valley current-mode control architecture. This allows the ADP1870/ ADP1871 to drive all N-channel power stages to regulate output voltages as low as 0.6 V. The ADP1871 is the power saving mode (PSM) version of the device and is capable of pulse skipping to maintain output regulation while achieving improved syste...