1. Products
  2. Power Management
  3. Switching Regulators
  4. DDR/QDR Memory Bus Termination
  5. MAX8550


Features and Benefits

  • Buck Controller
    • Quick-PWM with 100ns Load-Step Response
    • Up to 95% Efficiency
    • 2V to 28V Input Voltage Range
    • 1.8V/2.5V Fixed or 0.7V to 5.5V Adjustable Output
    • Up to 600kHz Selectable Switching Frequency
    • Programmable Current Limit with Foldback Capability
    • 1.7ms Digital Soft-Start and Independent Shutdown
    • Overvoltage/Undervoltage-Protection Option
    • Power-Good Window Comparator
  • LDO Section
    • Fully Integrated VTT and VTTR Capability
    • VTT has ±3A Sourcing/Sinking Capability
    • VTT and VTTR Outputs Track VREFIN/2
    • All-Ceramic Output-Capacitor Designs
    • 1.0V to 2.8V Input Voltage Range
    • Power-Good Window Comparator

Product Details

The MAX8550/MAX8551 integrate a synchronous-buck PWM controller to generate VDDQ, a sourcing and sinking LDO linear regulator to generate VTT, and a 10mA reference output buffer to generate VTTR. The buck controller drives two external N-channel MOSFETs to generate output voltages down to 0.7V from a 2V to 28V input with output currents up to 15A. The LDO can sink or source up to 1.5A continuous and 3A peak current. Both the LDO output and the 10mA reference buffer output can be made to track the REFIN voltage. These features make the MAX8550/MAX8551 ideally suited for DDR memory applications in desktops, notebooks, and graphic cards.

The PWM controller in the MAX8550/MAX8551 utilizes Maxim's proprietary Quick-PWM architecture with programmable switching frequencies of up to 600kHz. This control scheme handles wide input/output voltage ratios with ease and provides 100ns response to load transients while maintaining high efficiency and a relatively constant switching frequency. The MAX8550 offers fully programmable UVP/OVP and skip-mode options ideal in portable applications. Skip mode allows for improved efficiency at lighter loads. The MAX8551, which is targeted towards desktop and graphic-card applications, does not offer the pulse-skip feature.

The VTT and VTTR outputs track to within 1% of VREFIN/2. The high bandwidth of this LDO regulator allows excellent transient response without the need for bulk capacitors, thus reducing cost and size.

The buck controller and LDO regulators are provided with independent current limits. Adjustable lossless foldback current limit for the buck regulator is achieved by monitoring the drain-to-source voltage drop of the low-side MOSFET. Additionally, overvoltage and undervoltage protection mechanisms are built in. Once the overcurrent condition is removed, the regulator is allowed to enter soft-start again. This helps minimize power dissipation during a short-circuit condition. The MAX8550/MAX8551 allow flexible sequencing and standby power management using the active-low SHDNA, active-low SHDNB, and STBY inputs.

Both the MAX8550 and MAX8551 are available in a small 5mm x 5mm, 28-pin thin QFN package.


  • DDR I and DDR II Memory Power Supplies
  • Desktop Computers
  • Game Consoles
  • Graphic Cards
  • Networking
  • Notebooks and Desknotes
  • RAID

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Evaluation Kits (1)

Product Recommendations

MAX8550 Companion Parts

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
MAX8550ETI+ Material Declaration Reliability Data 28-LFCSP-5X5X0.75
MAX8550ETI+T Material Declaration Reliability Data 28-LFCSP-5X5X0.75
Wafer Fabrication Data MAX8550 Reliability Data

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