Overview
| Information | 18V 700KHz 8A Fast-PWM Synchronous Step-Down Converter |
|---|---|
| # of Outputs | 1 |
| IOUT (A) | 8 |
| VIN MIN (V) | 3 |
| VIN MAX (V) | 18 |
| IQ (µA) | - |
| VOUT MIN (V) | 0.6 |
| VOUT MAX (V) | 18 |
| Frequency (kHz) | 700 |
| Accuracy (%) | - |
| Efficiency (%) | 97.4 (5Vin to 3.3Vout, 2A) |
| Package | FC-QFN16 |
| X x Y Package Dimension (mm) | 3 x 3 |
| Control Mode | Fast pulse-width modulation (PWM) COT control |
| Special Features | - |
| Operating Temperature (°C) | -40 to 85 |
The MxL76508 is a fully integrated, high-efficiency synchronous step-down converter that requires a minimum number of external components. It offers a very compact solution with up to 8A continuous output current over a wide input range.
The MxL76508 uses a proprietary constant on-time (COT) control scheme that provides a superior transient response and maintains a constant switching frequency during continuous conduction mode (CCM) operation. The external ramp compensation network enables stable operation with ultra-low equivalent series resistance (ESR) output ceramic capacitors. An internal compensated error amplifier in the control loop provides excellent line and load regulation.
The MxL76508 integrates extensive protection functions, including 2.85V input under-voltage lockout (UVLO), thermal shutdown, input over-voltage protection (OVP), cycle-by-cycle current limiting, and short-circuit protection. An open-drain power good signal indicates that the output is within its regulation voltage range.
The MxL76508 offers three modes of operation, PFM (MxL76508N), UA (MxL76508U), and forced PWM—FPWM—(MxL76508A), to suit different applications. PFM mode provides high efficiency at light loads and low standby power. A mode can operate in DCM at light load and in CCM at higher output power, and the lowest frequency at light load is limited to a frequency not lower than that of the sound wave to avoid buzzing noise. FPWM mode provides low ripple voltage and fast transient, even at light loads.
The converter is available in a small 16-pin 3mm×3mm QFN package.
Input voltage range: 3V to 18V
1% feedback voltage accuracy
8A continuous output current
Supports 100% duty cycle low-dropout operation
Stable operation with low ESR ceramic output capacitors
Fast pulse-width modulation (PWM) COT control with superior transient performance
Constant 700KHz switching frequency
14mΩ/8mΩ integrated high-side (HS)/low-side (LS) power switches
Accurate 1.26V EN threshold with 260mV hysteresis
High-efficiency operation at light load (MxL76508N)
Ultra-sonic (UA) mode of operation (MxL76508U)
FPWM mode of operation (MxL76508A)
Low quiescent current of 200µA for MxL76508U_UA mode, low quiescent current of 150µA for MxL76508N_PFM mode
Internal fixed or external programmable soft-start time
Thermal shutdown
Hiccup mode short-circuit protection
Available in a 16-pin 3mm×3mm QFN package
USB Type-C/PD docking stations
Networking systems
Laptop computers
Flat panel television and monitors
Distributed power systems
Documentation & Design Tools
| Type | Title | Version | Date | File Size |
|---|---|---|---|---|
| Data Sheets | 18V 700KHz 8A Fast-PWM Synchronous Step-Down Converter | R01 | March 2025 | 4.4 MB |
| Product Brochures | Power Management Brochure | R03 | April 2025 | 6.2 MB |
Parts & Purchasing
| Part Number | Pkg Code | Min Temp | Max Temp | Notes | Status | Buy Now | Order Samples |
|---|---|---|---|---|---|---|---|
| MXL76508A-AQF-R | FC-QFN16 3x3 | -40 | 85 | FPWM mode (AQF), Non-China OSAT | Active | Order | |
| MXL76508A-BQF-R | FC-QFN16 3x3 | -40 | 85 | FPWM mode (BQF), China OSAT | Pre | ||
| MXL76508N-AQF-R | FC-QFN16 3x3 | -40 | 85 | PFM mode (AQF), Non-China OSAT | Active | Order | |
| MXL76508N-BQF-R | FC-QFN16 3x3 | -40 | 85 | PFM mode (BQF), China OSAT | Pre | ||
| MXL76508U-AQF-R | FC-QFN16 3x3 | -40 | 85 | Ultra-sonic (UA) mode (AQF), Non-China OSAT | Active | Order | |
| MXL76508U-BQF-R | FC-QFN16 3x3 | -40 | 85 | Ultra-sonic (UA) mode (BQF), China OSAT | Pre |
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.
Packaging
| Pkg Code | Details | Quantities | Dimensions |
|---|---|---|---|
| FC-QFN16 3x3 |
|
|
|
FAQs & Support
Search our list of FAQs for answers to common technical questions.
For material content, environmental, quality and reliability questions review the Quality tab or visit our Quality page.
For ordering information and general customer service visit our Contact Us page.
Submit a Technical Support Question As a New Question
Visit the product page for the part you are interested in. The part's status is listed in the Parts & Purchasing section. You can also view Product Lifecycle and Obsolescence Information including PDNs (Product Discontinuation Notifications).
To visit a product page, type the part into the search window on the top of the MaxLinear website.
In this example, we searched for XR33180. Visit the product page by clicking the part number or visit the orderable parts list by clicking "Orderable Parts".
The Parts & Purchasing section of the product page shows the Status of all orderable part numbers for that product. Click Show obsolete parts, to see all EOL or OBS products.
