Overview
| Information | 18V 720KHz 3A Fast-PWM Synchronous Step-Down Converter |
|---|---|
| # of Outputs | 1 |
| IOUT (A) | 3 |
| VIN MIN (V) | 4.5 |
| VIN MAX (V) | 18 |
| IQ (µA) | - |
| VOUT MIN (V) | 0.6 |
| VOUT MAX (V) | 18 |
| Frequency (kHz) | 720 |
| Accuracy (%) | - |
| Efficiency (%) | 96.5 (5Vin to 3.3Vout, 0.4A) |
| Package | SOT-23-6 |
| X x Y Package Dimension (mm) | - |
| Control Mode | Fast pulse-width modulation (PWM) COT control |
| Special Features | - |
| Operating Temperature (°C) | -40 to 85 |
The MxL76503 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 3A continuous output current over a wide input range.
The MxL76503 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 MxL76503 integrates extensive protection functions, including under-voltage lockout (UVLO), over-current protection (OCP), under-voltage protection (UVP), and thermal shutdown.
The MxL76503 offers two modes of operation, PFM (MxL76503N) and forced PWM—FPWM—(MxL76503A), to suit different applications. PFM mode provides high efficiency at light loads and low standby power. FPWM mode
provides low ripple voltage and fast transient, even at light loads.
The converter is available in a small 6-pin SOT23-6L package.
Input voltage range: 4.5V to 18V
Output voltage range: 0.6V to 18V
3A 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
720KHz switching frequency
1.2ms internal soft-start
80mΩ/56mΩ integrated high-side (HS)/low-side (LS) power switches
Accurate EN/UVLO threshold
High-efficiency operation at light load (MxL76503N)
FPWM mode of operation (MxL76503A)
Thermal shutdown with auto-recovery
Hiccup mode short-circuit protection
Available in a 6-pin SOT23-6L package
Laptop computers
Tablet PCs
Networking systems
Personal video recorders
Flat panel television and monitors
Distributed power systems
Documentation & Design Tools
| Type | Title | Version | Date | File Size |
|---|---|---|---|---|
| Data Sheets | 18V 720KHz 3A Fast-PWM Synchronous Step-Down Converter | R01 | March 2025 | 2.5 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 |
|---|---|---|---|---|---|---|---|
| MXL76503A-ASA-R | SOT-23-6 | -40 | 85 | FPWM mode (ASA), Non-China OSAT | Active | Order | |
| MXL76503A-BSA-R | SOT-23-6 | -40 | 85 | FPWM mode (BSA), China OSAT | Pre | ||
| MXL76503N-ASA-R | SOT-23-6 | -40 | 85 | PFM mode (ASA), Non-China OSAT | Active | Order | |
| MXL76503N-BSA-R | SOT-23-6 | -40 | 85 | PFM mode (BSA), 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 |
|---|---|---|---|
| SOT-23-6 |
|
|
|
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