Features and Benefits
- Input voltage range: 2.75 V to 20 V
- Output voltage range: 0.6 V to 90% VIN
- Maximum output current of more than 25 A
- Current mode architecture
- Configurable to voltage mode
- ±1% output voltage accuracy over temperature
- Voltage tracking
- Programmable frequency: 200 kHz to 1.5 MHz
- Synchronization input
- Power saving mode at light load
- Precision enable input
- Power good with internal pull-up resistor
- Adjustable soft start
- Programmable current sense gain
- Integrated bootstrap diode
- Starts into a precharged load
- Externally adjustable slope compensation
- Suitable for any output capacitor
- Overvoltage and overcurrent-limit protection
- Thermal overload protection
- Input undervoltage lockout (UVLO)
- Available in 16-lead, 4 mm × 4 mm LFCSP
- Supported by ADIsimPower design tool
The ADP1851 is a wide range input, dc-to-dc, synchronous buck controller capable of running from commonly used 3.3 V to 12 V (up to 20 V) voltage inputs. The device nominally operates in current mode with valley current sensing providing the fastest step response for digital loads. It can also be configured as a voltage mode controller with low noise and crosstalk for sensitive loads.
The ADP1851 is ideal in system applications requiring multiple output voltages. The ADP1851 includes a synchronization feature to eliminate beat frequencies between switching devices. It also provides accurate tracking capability between supplies and includes precision enable and power-good functions for simple, robust sequencing.
The ADP1851 provides a high speed, high peak current gate driving capability to enable energy efficient power conversion. The device can be configured to operate in power saving mode by skipping pulses, reducing switching losses, and improving efficiency at light load and standby conditions.
The accurate current limit allows design within a narrower range of tolerances and can reduce overall converter size and cost. The ADP1851 can regulate down to 0.6 V output using a high accuracy reference with ±1% tolerance over the temperature range of −40°C to +125°C.
With its wide range input voltage, the ADP1851 provides the designer with maximum flexibility for use in a variety of system configurations; loop compensation, soft start, frequency setting, power saving mode, current limit, and current sense gain can all be programmed using external components. In addition, the external RAMP resistor allows the selection of optimal slope and VIN feedforward in both current and voltage modes for excellent line rejection. The linear regulator and the bootstrap diode for the high-side driver are internal.
Protection features include undervoltage lockout, overvoltage, overcurrent/short circuit, and overtemperature.
- Intermediate bus and POL systems requiring sequencing and tracking, including
- Telecom base station and networking
- Industrial and instrumentation
- Medical and healthcare
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)
This describes the design, operation, and test results of the ADP1851-EVALZ. The input range for this evaluation board is 9 V to 15 V, and the regulated output voltage is 1.8 V with a maximum 25 A output current. A switching frequency (fSW) of 600 kHz is chosen to achieve a good balance between efficiency and the sizes of the power components.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADIsimPE, which is powered by SIMetrix/SIMPLIS, is a circuit simulation suite optimized for the design and development of analog and mixed signal circuits. SIMetrix mode is ideal for the simulation of general non-switching circuits. It provides full Pspice compatibility for use with industry-standard SPICE models. SIMPLIS (SIMulation Piecewise-Linear System) mode simulates the operation of switching circuits with vastly improved robustness, speed, and accuracy compared to standard SPICE. It is particularly useful for switching power supply, PLLs, and ADC/DAC applications.
ADIsimPower is the fastest and most accurate Power Management design tool. ADI's Design Center lets you design your power circuits in three easy steps.
Microsoft Excel download tool from ADIsimPower to generate a power supply design complete with a schematic, bill of materials, and performance specifications.
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.
Sample & Buy
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.