1. Products
  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. Internal Power Switch Buck Regulators
  6. MAX17645


Features and Benefits

  • Reduces External Components and Total Cost
    • No Schottky—Synchronous Operation
    • Internal Control Loop Compensation
    • Internal Soft-Start
    • All Ceramic Capacitors, Ultra-Compact Layout
  • Reduces Number of DC-DC Regulators to Stock
    • Wide 4.5V to 36V Input Voltage Range
    • Adjustable Output from 0.9V up to 89% of VIN
    • Delivers Up to 1A Load Current
  • High Efficiency
    • 90% Full-Load Efficiency (VIN = 24V, VOUT = 5V, IOUT = 1A)
    • 2.2μA (typ) Shutdown Current
    • High Light-Load Efficiency with PFM Mode (MAX17645D)
  • Flexible Design
    • Programmable EN/UVLO Threshold
    • Monotonic Startup into Prebiased Output
    • Open-Drain Output (Actiive-Low RESET) for Output Status Monitoring
  • Robust Operation
    • Built-In Hiccup Mode Overload Protection
    • Overtemperature Protection
    • CISPR32 Class B Compliant
    • Wide -40°C to +125°C Ambient Operating Temperature/-40°C to +150°C Junction Temperature

Product Details

The MAX17645 is a high-efficiency, high voltage, synchronous step-down DC-DC converter with integrated MOSFETs, operates over a 4.5V to 36V input. It can deliver up to 1A load current. The MAX17645 operates at 650kHz switching frequency. The MAX17645B operates in pulse-width modulation (PWM) mode at all loads. The MAX17645D operates in pulse-frequency modulation (PFM) mode at light loads. The output voltage is programmable from 0.9V up to 89% of VIN. Built-in control loop compensation across the output voltage range eliminates the need for external compensation components. The feedback voltage regulation accuracy over -40°C to +125°C is ±1.1%.

The device features a peak-current-mode control architecture. In this architecture, while operating in PWM mode the part sets the duty cycle using a transconductance error amplifier, a PWM comparator, a high-side current-sense amplifier, and a slope-compensation generator. At each rising edge of the clock, the high-side MOSFET turns on and remains on until either the appropriate or maximum duty cycle is reached, or the peak current limit is detected. During the high-side MOSFET’s on-time, the inductor current ramps up. During the rest of the switching cycle, the high-side MOSFET remains off and the low-side MOSFET remains on, inductor current ramps down. An appropriate dead time is implemented between the high-side and low-side state transitions to avoid cross conduction.

A fixed soft-start time of 3.15ms (typ) allows users to reduce input inrush current. The device also features an enable/undervoltage lockout pin (EN/UVLO) that allows the user to turn on the part at the desired input-voltage level. An open-drain active-low RESET feature provides a power-good signal to the system upon achieving successful regulation of the output voltage.


  • Factory Automation
  • Aftermarket Market Automation
  • General Point of Load

Product Lifecycle icon-recommended 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 (2)

Tools & Simulations

EE-Sim® Power Tools

The EE-Sim DC-DC Converter Tool uses your requirements to quickly create a complete power design including a schematic, BOM with commercially available parts, and time and frequency domain simulations. Your customized schematic can be downloaded for further analysis in the standalone EE-Sim OASIS Simulator, featuring SIMPLIS and SIMetrix SPICE engines.


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.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
MAX17645BATA+ Material Declaration Reliability Data Thin Dual Flatpack No Leads
MAX17645BATA+T Material Declaration Reliability Data Thin Dual Flatpack No Leads
MAX17645DATA+ Material Declaration Reliability Data Thin Dual Flatpack No Leads
MAX17645DATA+T Material Declaration Reliability Data Thin Dual Flatpack No Leads
Wafer Fabrication Data

PCN-PDN Information

Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.

Sample & Buy

Ordering FAQs

See our Ordering FAQs for answers to questions about online orders, payment options and more.


Buy Now Pricing

(**) Displayed Buy Now Price and Price Range is based on small quantity orders.


List Pricing

(*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


Lead Times

Please see the latest communication from our CCO regarding lead times.



Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.

Price Table Help