Automotive Mobile Audio Video

Optimized for RF power amplifiers in 2.5G and 3G CDMA and W-CDMA mobile phones, 2 MHz PWM synchronous Model MIC2224 features 2.7-5.5 V input voltage with DAC-adjustable output from 0.3-3.6 V. By adjusting voltage applied to RF power amplifier, transmit power can be made to match environmental operating conditions. In PWM mode, MIC2224 supplies more than 600 mA of output current through fully integrated MOSFET switches. In by-pass mode, it sources in excess of 1 A to load.

SAN JOSE, Calif., Feb. 8 - Micrel, Inc. (NASDAQ:MCRL), an industry leader in Power, Connect and Protect IC solutions, today announced the MIC2224, a new high efficiency, 2MHz PWM synchronous buck switching regulator optimized for RF power amplifiers in 2.5G and 3G CDMA and W-CDMA mobile phones. The device is ideal for these single-cell Li-Ion battery applications and meets the most stringent Vout response specifications of next generation cell phones. The MIC2224 is currently sampling with volume quantities available within 10-12 weeks. Pricing starts at $1.91 in 1K quantity.

"The MIC2224 is targeted specifically for the industry's most advanced cell phone needs," said Tony O'Brien, Micrel's director of marketing, power products. "The chip provides the industry's most efficient use of battery power while the 2MHz PWM operation allows for the smallest possible components."

MIC2224's output voltage can be dynamically adjusted with an external DAC to maximize talk time of the cell phone. By adjusting the voltage applied to the RF power amplifier, transmit power can be made to match environmental operating conditions. When close to a base station, output power can be set low, while in weak signal areas, the phone may require increased transmit power to maintain a reliable connection. In maximum power situations, the MIC2224 has a by-pass mode which connects the RF PA directly to the battery, providing maximum current to the load. This internal 40mOhm, bypass switch is automatically activated when the DAC control voltage exceeds a preset level.

The IC features a 2.7V to 5.5V input voltage range with a DAC-adjustable output voltage from 0.3V up to 3.6V. In PWM mode, the MIC2224 will supply more than 600mA of output current through its fully integrated MOSFET switches. In by-pass mode, it can source in excess of 1 Amp to the load. Operating at constant frequency, with a duty cycle ranging from 0 to 100 percent, the MIC2224's 2MHz switching rate and internal control loop are optimized for operation with the smallest possible components. This makes it the ideal choice for space constrained portable appliances.

The MIC2224 is fully protected against output faults and extreme operating conditions by output current limiting in PWM and Bypass modes, and on-chip thermal sensing and shut-down. The chip is available in tiny 3mm x 3mm MLFTM-10L Pb-free packaging.

"The global cell phone market continues to grow, and functionality increases with each new product turn," noted Bob Whelton, executive vice president operations, Micrel. "The MIC2224 enables mobile phone manufacturers to manage challenging battery power requirements while meeting stringent 2.5G and 3G CDMA power specifications with a board space and cost efficient IC option."

About Micrel, Inc.

Micrel, Inc. is a leading global manufacturer of Power, Connect and Protect IC solutions for the worldwide analog, Ethernet and high bandwidth markets. The Company's products include advanced mixed-signal, analog and power semiconductors; high performance communication, clock management, Ethernet switch and physical layer transceiver ICs. Company customers include leading manufacturers of enterprise, consumer, industrial, mobile, telecommunications, automotive, and computer products. Corporation headquarters and state-of-the-art wafer fabrication facilities located in San Jose, CA with regional sales and support offices and advanced technology design centers situated throughout the Americas, Europe and Asia.