Micrel's Power Management IC For 2.5G And 3G Mobile Handsets

Imagine a chip that can lower your cell phone’s power usage when it doesn’t need it, and can increase it when it does - like when it needs to pump up the juice in weak signal areas. Micrel Inc just let us know about the MIC2807, a high performance power management IC that provides an RF solution for UMTS, EDGE, CDMA2000 and WCDMA handsets. The new device, housed in a tiny 2.5mm x 2.8mm MLF package, provides a total of three outputs ; a 2MHz buck regulator and two low noise linear regulators. The device is suitable for next-generation 3G handsets as well as WiBro and WiFi applications. The output voltage of the buck regulator in the MIC2807 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 MIC2807 has a by-pass mode which connects the RF PA directly to the battery, thereby providing maximum current to the load. This internal 75mOhm bypass switch is automatically activated when the DAC control voltage exceeds a preset level. The MIC2807 is currently available in volume with pricing starting at $2.50 for 1K quantity.