Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches

The MAX15041 low-cost, synchronous DC-DC converter with internal switches delivers an output current up to 3A. The MAX15041 operates from an input voltage of 4.5V to 28V and provides an adjustable output voltage from 0.606V to 90% of VIN, set with two external resistors. The MAX15041 is ideal for distributed power systems, preregulation, set-top boxes, television, and other consumer applications.

The MAX15041 features a peak-current-mode PWM controller with internally fixed 350kHz switching frequency and a 90% maximum duty cycle. The current-mode control architecture simplifies compensation design, and ensures a cycle-by-cycle current limit and fast response to line and load transients. A high-gain transconductance error amplifier allows flexibility in setting the external compensation by using a type II compensation scheme, thereby allowing the use of all ceramic capacitors.

This synchronous buck regulator features internal MOSFETs that provide better efficiency than asynchronous solutions, while simplifying the design relative to discrete controller solutions. In addition to simplifying the design, the integrated MOSFETs minimize EMI, reduce board space, and provide higher reliability by minimizing the number of external components.

The MAX15041 also features thermal shutdown and overcurrent protection (high-side sourcing and low-side sinking), and an internal 5V LDO with undervoltage lockout. In addition, this device ensures safe startup when powering into a prebiased output.

Other features include an externally adjustable soft-start that gradually ramps up the output voltage and reduces inrush current. Independent enable control and power-good signals allow for flexible power sequencing.

The MAX15041 is available in a space-saving, high-power, 3mm x 3mm, 16-pin TQFN-EP package and is fully specified from -40°C to +85°C.

Applications

* Consumer Products * Distributed Power Systems * Preregulators * Set-Top Boxes * Televisions * Wall Adapters * XDSL Modems

* Up to 3A of Continuous Output Current

* ±1% Output Accuracy Over Temperature

* 4.5V to 28V Input Voltage Range

* Adjustable Output Voltage Range from 0.606V to 0.9 x VIN

* Internal 170mΩ RDS-ON High-Side and 105mΩ RDS-ON Low-Side Power Switches

* Fixed 350kHz Switching Frequency

* Up to 93% Efficiency

* Cycle-By-Cycle Overcurrent Protection

* Programmable Soft-Start

* Stable with Low-ESR Ceramic Output Capacitors

* Safe Startup into Prebiased Output

* Enable Input and Power-Good Output

* Fully Protected Against Overcurrent and Overtemperature

* VDD LDO Undervoltage Lockout

* Space-Saving, Thermally Enhanced, 3mm x 3mm Package