MAX8504

ABSOLUTE MAXIMUM RATINGS
BATTP, BATT, OUT, SHDN, SKIP, HP,
REFIN, FB to GND ....................................................-0.3V to +6V
PGND to GND .......................................................-0.3V to +0.3V
REF, COMP to GND .................................-0.3V to (VBATT + 0.3V)
LX Current (Note 1) ...........................................................2.25A
Output Short-Circuit Duration .......................................Indefinite
Continuous Power Dissipation (TA = +70°C)
12-Lead Thin QFN (derate 16.9mW/°C above +70°C) .1349mW
Operating Temperature Range .........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range ...........................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C

Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Note 1: LX has internal clamp diodes to PGND and BATTP. Applications that forward bias these diodes should take care not to exceed the IC's package power dissipation limits.

The MAX8500MAX8504 PWM DC-to-DC buck converters are optimized with integrated bypass FET (0.25 typ) to provide power to the PA in N-CDMA and W-CDMA cell phones. The MAX8504 have a low on-resistance FET to bypass the external inductor for low dropout of only 150mV at 600mA load, regardless of inductor series resistance. The supply voltage range is from 2.6V to 5.5V and the guaranteed converter output current is 600mA. The 1MHz PWM switching frequency of MAX8504 allows for small external components.

The MAX8500MAX8503 are dynamically controlled to provide varying output voltages from 0.4V to VBATT. The LDO regulation point is slightly lower than the PWM converter such that the transition into and out of dropout is smooth, regardless of the inductor resistance. The MAX8504 is programmed for fixed 1.25V to 2.5V output with external resistors. It features a high-power bypass mode that connects the output directly to the battery. MAX8504 are  esigned to achieve an output settling time of less than 30s for a full-scale change in output voltage and load  urrent.

The MAX8500MAX8504 are available in a 12-lead 4mm x 4mm thin QFN package (0.8mm max height).