ADP1873 Synchronous Current-Mode Buck Controller with Constant On-time, 0.6 V Reference Voltage, and Power Saving Mode

The ADP1872/ADP1873 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 current-sense gain, current-control scheme. In addition, these devices offer optimum performance at low duty cycles by utilizing valley current-mode control architecture. This allows the ADP1872/ ADP1873 to drive all N-channel power stages to regulate output voltages as low as 0.6 V. The ADP1873 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. Available in three frequency options (300 kHz, 600 kHz, and 1.0 MHz), the ADP1872/ADP1873 are well suited for a wide range of applications. These ICs not only operate from a 2.75 V to 5.5 V bias supply, but also can accept a power input as high as 20 V. 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 pre¬charged output. The low-side current-sense, current-gain scheme, along with the PSM/forced pulse-width modulation (PWM) option, reduces the external part count and improves efficiency. The ADP1872/ADP1873 operate over the –40°C to +125°C junction temperature range and are available in a 10-lead MSOP. Applications Telecom and networking systems Mid to High End servers Set-top boxes DSP core power supplies

Available in three frequency options (300 kHz, 600 kHz, and 1.0 MHz), the ADP1872/ADP1873 are well suited for a wide range of applications. These ICs not only operate from a 2.75 V to 5.5 V bias supply, but also can accept a power input as high as 20 V.

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 pre¬charged output. The low-side current-sense, current-gain scheme, along with the PSM/forced pulse-width modulation (PWM) option, reduces the external part count and improves efficiency. The ADP1872/ADP1873 operate over the –40°C to +125°C junction temperature range and are available in a 10-lead MSOP.

Features and Benefits
  • Power input voltage as low as 2.75 V to 20 V
  • Bias supply voltage range:
    2.75 V to 5.5 V
  • 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 (ADP1873 only)
  • Resistor Programmable Current Sense Gain
  • Thermal overload protection
  • Short-circuit protection
  • See data sheet for additional features
Power Management
Design Tools
Data Sheets
Documentnote
ADP1872/ADP1873: Synchronous Current-Mode with Constant On-Time, PWM Buck Controller Data Sheet (Rev. B)PDF 2049 kB
User Guides
Documentnote
UG-057: Evaluating the ADP1872/ADP1873 PWM Buck ControllersPDF 1277 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
ADP1873ARMZ-0.3-R7 Production10 ld MSOPREEL 1000-40 to 125C01.03Y
ADP1873ARMZ-0.6-R7 Production10 ld MSOPREEL 1000-40 to 125C01.03Y
ADP1873ARMZ-1.0-R7 Last Time Buy10 ld MSOPREEL 1000-40 to 125C01.03Y
Evaluation Boards
Part NumberDescriptionPriceRoHS
ADP1873-0.3-EVALZEvaluation Board60Y
ADP1873-0.6-EVALZEvaluation Board60Y
ADP1873-1.0-EVALZEvaluation Board60Y
ADP1872/ADP1873: Synchronous Current-Mode with Constant On-Time, PWM Buck Controller Data Sheet (Rev. B) adp1872
ADP187x Buck Designer Tool adp1872
UG-057: Evaluating the ADP1872/ADP1873 PWM Buck Controllers adp1872