ADP1871 Synchronous Buck Controller with Constant On-Time, Valley Current Mode, and Power Save Mode

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 system efficiency at light loads (see the Power Saving Mode (PSM) Version (ADP1871) section for more information).

Available in three frequency options (300 kHz, 600 kHz, and 1.0 MHz, plus the PSM option), the ADP1870/ADP1871 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 LDO.

In addition, an internally fixed soft start period is included to limit input in-rush current from the input supply during startup and to provide reverse current protection during soft start for a precharged output. The low-side current-sense, current-gain scheme and integration of a boost diode, along with the PSM/forced pulsewidth modulation (PWM) option, reduce the external part count and improve efficiency.

The ADP1870/ADP1871 operate over the -40°C to +125°C junction temperature range and are available in 10-lead MSOP package.

Features and Benefits
  • 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
  • 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 package
Power Management
Design Tools
Data Sheets
Documentnote
ADP1870/ADP1871: Synchronous Buck Controller with Constant On-Time and Valley Current Mode Data Sheet (Rev. B)PDF 1861 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
ADP1871ACPZ-0.3-R7 Production10 ld LFCSP (3x3mm)REEL 1500-40 to 125C01.08Y
ADP1871ACPZ-0.6-R7 Production10 ld LFCSP (3x3mm)REEL 1500-40 to 125C01.08Y
ADP1871ACPZ-1.0-R7 Production10 ld LFCSP (3x3mm)REEL 1500-40 to 125C01.08Y
ADP1871ARMZ-0.3-R7 Production10 ld MSOPREEL 1000-40 to 125C01.08Y
ADP1871ARMZ-0.6-R7 Production10 ld MSOPREEL 1000-40 to 125C01.08Y
ADP1871ARMZ-1.0-R7 Production10 ld MSOPREEL 1000-40 to 125C01.08Y
Evaluation Boards
Part NumberDescriptionPriceRoHS
ADP1871-0.3-EVALZEvaluation Board60Y
ADP1871-0.6-EVALZEvaluation Board60Y
ADP1871-1.0-EVALZEvaluation Board60Y
ADP1870/ADP1871:具有恒定导通时间和谷值电流模式的同步降压控制器 数据手册 (Rev. B) adp1870
ADP1870/ADP1871: Synchronous Buck Controller with Constant On-Time and Valley Current Mode Data Sheet (Rev. B) adp1870
ADP187x Buck Designer Tool adp1872