HIGHEST EFFICIENCY DC-DC INTEGRATES 75m BYPASS FET AND INCREASES BATTERY LIFE IN CELLULAR PHONES
SUNNYVALE, CA-February 23, 2004-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX8506/MAX8507/MAX8508, the highest efficiency, lowest dropout, step-down DC-DC converters. These devices are ideal for driving the linear power amplifier (PA) used in cdmaOne™ and WCDMA cellular phones. The high-speed MAX8506/MAX8507 vary their output voltage from 0.4V to 3.4V in less than 30µs, thereby adjusting the power applied to the PA. This tracking of the transmit power improves efficiency up to 47% at +10dBm and is dynamically controlled from the phone's baseband processor. The MAX8508 is programmed for fixed 0.75V to 3.4V output with external resistors.
The MAX8506/MAX8507/MAX8508 are pulse-width modulated (PWM) converters with 1MHz switching frequency and deliver up to 600mA. These devices have a 2.6V to 5.5V input range for use with a single lithium-ion (Li+) battery. The integrated bypass FET (75m typ) operates directly from the battery with 38mV dropout at 600mA (75m in parallel with 400m switcher), minimizing power loss through the inductor and sustaining battery life. The MAX8506/MAX8507/MAX8508 operate up to 100% duty cycle. Quiescent supply current is only 180µA and drops to 0.1µA in logic-controlled shutdown.
The MAX8506/MAX8507/MAX8508 are packaged in a 16-pin thin QFN (4mm x 4mm x 0.8mm) and are screened for the extended temperature range (-40°C to +85°C). Prices start at $2.05 (1000-up, FOB USA). An evaluation kit is available to speed designs.
cdmOne is a trademark of CDMA Development Group.
|
