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ADP1870
Synchronous Buck Controller with Constant On-Time and Valley Current Mode
Overview
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
- 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
Product Details
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.
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Documentation
Tools & Simulations
Design Tools
Microsoft Excel download tool from ADIsimPower to generate a power supply design complete with a schematic, bill of materials, and performance specifications.
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.