Micrel Launches Small Dual Synchronous Buck Converter

Micrel Inc. launched the MIC23250, which the company describes as the industry’s smallest high efficient, dual 400mA 4 MHz PWM synchronous buck step-down converter housed in a tiny 2 x 2mm, 10 lead MLF® package.

The device is said to be well suited for 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 is said to achieve high efficiency, very low output ripple, and fast transient response while using very small output capacitors.

"With the world’s smallest solution, the MIC23250 gives portable system designers the ability to extend battery life with two high efficiency Hyper Light Load™ output rails and still maintain a tiny circuit footprint," noted Andy Cowell, Micrel’s Vice President of Marketing for Analog. "The 2 x 2mm package and 4MHz switching speed, which allows the use of 1µH to 2.2µH inductors, equates to the smallest dual portable power solution on the market today."

The MIC23050 is suitable for 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-dc converters which eliminates the need for external MOSFETs. The device accommodates an input voltage range of 2.7 to 5.5V, and has fixed preset output voltage options down to as low as 0.72V. 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 35µA 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 3mV output voltage ripple in full PWM mode. With up to 94% peak efficiency and approximately 85% at 1µA load, the MIC23250 is said to be a suitable choice where size, efficiency and low noise are paramount design considerations. The MIC23250 is available in a tiny 10-pin 2 x 2mm MLF® with a junction operating range from -40 to +125°C.

The MIC23250 is available in volume with pricing starting at $1.47 for 1K quantities.