High-Efficiency, 4A, 1MHz, Step-Down Regulators with Integrated Switches in 2mm x 2mm Package

The MAX15050/MAX15051 high-efficiency switching regulators deliver up to 4A load current at output voltages from 0.6V to (0.9 x VIN). The devices operate from 2.9V to 5.5V, making them ideal for on-board point-of-load and postregulation applications. Total output-voltage accuracy is within ±1% over load, line, and temperature.

The MAX15050/MAX15051 feature 1MHz fixed-frequency PWM operation. The MAX15050 features pulse-skip mode to improve light-load efficiency. The MAX15050 soft-starts in a monotonic mode and then operates in the forced PWM mode or pulse-skip mode depending on the output load current condition. The MAX15051 soft-starts in the monotonic mode and operates in the forced PWM mode. The high operating frequency allows for small-size external components.

The low-resistance on-chip nMOS switches ensure high efficiency at heavy loads while minimizing critical parasitic inductances, making the layout a much simpler task with respect to discrete solutions. Following a simple layout and footprint ensures first-pass success in new designs.

The MAX15050/MAX15051 incorporate a high-bandwidth (> 26MHz) voltage-error amplifier. The voltage-mode control architecture and the voltage-error amplifier permit a type III compensation scheme to achieve maximum loop bandwidth, up to 200kHz. High loop bandwidth provides fast transient response, resulting in less required output capacitance and allowing for all-ceramic capacitor designs.

The MAX15050/MAX15051 feature an output overload hiccup protection and peak current limit on both high-side and low-side MOSFETs. These features provide for ultra-safe operation in the cases of short-circuit conditions, severe overloads, or in converters with bulk electrolytic capacitors.

The MAX15050/MAX15051 feature an adjustable output voltage. The output voltage is adjustable by using two external resistors at the feedback or by applying an external reference voltage to the REFIN/SS input. The MAX15050/MAX15051 offer programmable soft-start time using one capacitor to reduce input inrush current. A built-in thermal shutdown protection assures safe operation under all conditions. The MAX15050/MAX15051 are available in a 2mm x 2mm, 16-bump (4 x 4 array), 0.5mm pitch WLP package.

Applications

* ASIC/CPU/DSP Core and I/O Voltages * Base-Station Power Supplies * DDR Power Supplies * Point-of-Load * Portable Applications * RAID Control Power Supplies * Server Power Supplies * Telecom and Networking Power Supplies

* Internal 18mΩ RDS(ON) MOSFETs

* Pulse-Skip Mode for High-Efficiency Light Load (MAX15050)

* Continuous 4A Output Current

* ±1% Output-Voltage Accuracy Over Load, Line, and Temperature

* Operates from 2.9V to 5.5V Supply

* Adjustable Output from 0.6V to (0.9 x VIN)

* Adjustable Soft-Start Reduces Inrush Supply Current

* Factory-Trimmed 1MHz Switching Frequency

* Compatible with Ceramic, Polymer, and Electrolytic Output Capacitors

* Safe Startup Into Prebias Output

* Enable Input/Power-Good Output

* Fully Protected Against Overcurrent and Overtemperature

* Overload Hiccup Protection

* Sink/Source Current for DDR Applications

* 2mm x 2mm, 16-Bump (4 x 4 Array), 0.5mm Pitch WLP Package