Product category:
Power Supply ICs and Controllers
News Release from: Micrel | Subject: MIC2807 power-management IC
Edited by the Electronicstalk Editorial
Team on 06 March 2007
Chip manages power in 3G handsets
Power-management chip to boost efficiency of RF subsystems in next-generation 3G handsets.
Micrel Semiconductor's MIC2807 is a high-performance power-management IC for RF applications in UMTS, EDGE, CDMA2000 and WCDMA handsets The new device, housed in a tiny 2.5 x 2.8mm MLF package, provides a total of three outputs; a 2MHz buck regulator and two low-noise linear regulators
This article was originally published on Electronicstalk on 5 Dec 2000 at 8.00am (UK)
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The device is suitable for next-generation 3G handsets as well as WiBro and WiFi applications.
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"As cell phone providers deploy 3G networks and the mobile phone migrates from a voice-centric device to a media-centric one, the RF PA (power amplifier) will be one of the highest consumers of battery life", says Ralf Muenster, Micrel's Director of Marketing, Power Products.
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"The MIC2807 is specifically targeted at making the RF PA more efficient".
"Besides offering an efficient power supply for the PA, the MIC2807 has two extremely low-noise LDOs that are ideal for powering the RF transceiver and providing a highly accurate bias supply".
The output voltage of the buck regulator in the MIC2807 can be dynamically adjusted with an external DAC to maximise 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, whereas 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 IC includes a 2.7 to 5.5V input voltage range with a DAC-adjustable output voltage from 0.3 to 3.6V.
In PWM mode, the MIC2807 buck regulator will supply more than 600mA of output current through its fully integrated MOSFET switches.
In bypass mode, it can source in excess of 1A to the load.
One of the linear regulators within the device can provide up to 200mA and is suitable for powering the RF transceiver while the other can source up to 30mA.
Both linear regulators have a high ripple rejection of 70db at 1kHz and a low output noise of 32uV RMS typically.
The MIC2807 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 MIC2807 is currently available in volume with pricing starting at US $2.50 for 1,000.
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