Micrel Launches High Efficiency Dual Synchronous Buck Converter

Micrel launched the MIC23250, the industry’s smallest high efficient, dual 400 mA 4 MHz PWM synchronous buck step-down converter housed in a tiny 2 mm x 2 mm, 10 lead MLF® package. This device is ideally suited for today’s portable applications where high efficiency, low output ripple and small size are crucial. The MIC23250 utilizes a proprietary switching method called “Hyper Light Load™” that achieves high efficiency, very low output ripple, and fast transient response while using very small output capacitors. The MIC23250 is available in volume with pricing starting at $1.47 for 1K quantities.

This combination of high efficiency and fast transient response makes the MIC23250 a perfect choice to power the latest generation of low-voltage microprocessor cores and peripheral devices for mobile handsets, GPS, PDAs, portable media players (PMP), other portable devices. The MIC23250 integrates two synchronous rectified DC-to-DC converters which eliminates the need for external MOSFETs. The device accommodates an input voltage range of 2.7 V to 5.5 V, and has fixed preset output voltage options down to as low as 0.72 V. Under normal loads, the MIC23250 features 4MHz CCM PWM operation mode and automatically transitions to a variable frequency Hyper Light Load™ operation mode during light load conditions to maintain very high efficiency. The MIC23250 also features 35 µA typical quiescent current (both regulators operating), ultra-fast line and load transient response. This, while providing a low voltage output ripple of 20mVpp in Hyper Light Load™ mode and less than 3 mV output voltage ripple in full PWM mode. With up to 94 % peak efficiency and approximately 85 % at 1 mA load, the MIC23250 is a perfect choice where size, efficiency and low noise are paramount design considerations. The MIC23250 is available in a tiny 10-pin 2 mm x 2 mm MLF® with a junction operating range from -40^oC to +125^oC.