San Jose, Calif. Micrel Inc. has introduced the MIC23250, which it clams is the industry's smallest high-efficient, dual 400-mA PWM synchronous buck step-down converter housed in a 2 x 2-mm, 10-lead MLF package. The MIC23250 uses a proprietary switching method called Hyper Light Load, which is said to deliver high efficiency, very low output ripple, and fast transient response while using very small output capacitors.
The combination of the small package size and 4-MHz switching speed allows the use of 1 uH and 2.2 uH inductors, which provides the smallest dual portable power solution, said Micrel. In addition, the high efficiency and fast transient response make the MIC23050 well-suited 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/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 provides fixed preset output voltage options down to as low as 0.72 V. Under normal loads, the MIC23250 features 4-MHz 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 uA typical quiescent current (both regulators operating), ultra-fast line and load transient response. The device provides a low-voltage output ripple of 20 mVpp in Hyper Light Load mode and less than 3 mV output voltage ripple in full PWM mode. With up to 94 percent peak efficiency and approximately 85 percent at 1 mA load, the MIC23250 is suited for applications where size, efficiency and low noise are key design concerns. Junction operating temperature ranges from -40°C to +125°C.
Pricing: The MIC23250 is available in volume with pricing starting at $1.47 in quantities of 1,000.
Micrel , www.micrel.com