The MAX8506/MAX8507/MAX8508 integrate a PWM stepdown DC-DC regulator and a 75m (typ) bypass FET to power the PA in WCDMA and cdmaOneTM cell phones. The supply voltage range is from 2.6V to 5.5V, and the guaranteed output current is 600mA. One megahertz PWM switching allows for small external components. The MAX8506 and MAX8507 are dynamically controlled to provide varying output voltages from 0.4V to 3.4V. The MAX8508 is externally programmed for fixed 0.75V to 3.4V output. Digital logic enables a high-power (HP) bypass mode that connects the output directly to the battery for all versions. The MAX8506/MAX8507/MAX8508 are designed so the output settles in less than 30s for a full-scale change in output voltage and load current. The MAX8506/MAX8507/MAX8508 are offered in 16-pin 4mm x 4mm thin QFN packages (0.8mm max height).