ADP1875 Synchronous Buck Controller with Constant On-Time, Valley Current Mode, and Power Saving Mode

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).

In addition, soft start programmability is included to limit input inrush current from the input supply during startup and to provide reverse current protection during precharged output conditions. 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 ADP1874/ADP1875 operate over the −40°C to +125°C junction temperature range and are available in a 16-lead QSOP package.

APPLICATIONS
  • Telecom and networking systems
  • Mid- to high-end servers
  • Set-top boxes
  • DSP core power supplies
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 (ADP1875 only)
  • Resistor programmable current limit
  • See data sheet for additional features
Power Management
Design Tools
Data Sheets
Documentnote
ADP1874_AD1875: Synchronous Buck Controller with Constant On-Time and Valley Current Mode Data Sheet (Rev. A)PDF 2475 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
ADP1875ARQZ-0.3-R7 Production16 ld QSOPREEL 1000-40 to 125C01.32Y
ADP1875ARQZ-0.6-R7 Production16 ld QSOPREEL 1000-40 to 125C01.32Y
ADP1875ARQZ-1.0-R7 Production16 ld QSOPREEL 1000-40 to 125C01.32Y
Evaluation Boards
Part NumberDescriptionPriceRoHS
ADP1875-0.3-EVALZEvaluation Board60Y
ADP1875-0.6-EVALZEvaluation Board60Y
ADP1875-1.0-EVALZEvaluation Board60Y
ADP1874_AD1875: Synchronous Buck Controller with Constant On-Time and Valley Current Mode Data Sheet (Rev. A) adp1874
ADP187x Buck Designer Tool adp1872