MAX8594

♦ Minimum External Components
♦ Efficient Step-Down DC-DC Powers CPU Core
♦ 1V/1.3V Selectable Core Voltage, 400mA MAX8594)
♦ 1.3V/1.8V Selectable Core Voltage, 400mA MAX8594A)
♦ Main LDO 3.3V, 500mA
♦ SD Card Output 3.3V, 500mA
♦ Second Core LDO 1.8V, 50mA
♦ High-Efficiency LCD Boost
♦ LCD 0V True Shutdown when Off
♦ 46µA Quiescent Current

ABSOLUTE MAXIMUM RATINGS
IN, PV, ENSD, ENC1, ENC2, ENL, RS, SDIG,
LBI, DBI to GND ......................................................-0.3V to +6V
LXL to GND ............................................................-0.3V to +30V
MAIN, COR1, COR2, REF, LFB, CV, ENM, LBO, DBO,
LXC, SW to GND...........................................-0.3V to (VIN + 0.3V)
PV to IN..................................................................-0.3V to +0.3V
PGND to GND .........................................................-0.3V to +0.3V
Current into LXL..........................................................300mARMS
Current out of SW .......................................................300mARMS
Current into LXC .........................................................400mARMS
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (TA = +70°C)
24-Pin Thin QFN Package
(derate 20.8mW/°C above +70°C).................................1.67W
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.

The MAX8594/MAX8594A complete power-management hips for low-cost personal digital assistants As) operates from a 1-cell lithium-ion (Li+) or 3-cell NiMH battery. MAX8594 include all regulators, outputs, and oltage monitors necessary for small portable devices hile requiring a bare minimum of external components. eatured are three linear regulators, a boost DCDC onverter for LCD bias, an efficient 4MHz buck C-DC converter for core power, a croprocessor (µP) reset output, and low-battery shutdown in a 0.8mm igh thin QFN package.

The COR1 buck DC-DC converter MAX8594 supplies a pin-selectable utput at 400mA. All linear regulators feature MOS pass elements for efficient low-dropout operation. MAIN LDO supplies 3.3V at 500mA. A securedigital SD) card slot output upplies 3.3V at 500mA, nd a COR2 LDO supplies 1.8V at 50mA. Each output as MAX8594's own logic-controlled enable. For other output oltage combinations, ntact Maxim.

An LCD bias boost DC-DC converter MAX8594 features an onboard MOSFET and True Shutdown™ when off. This means that during shutdown, input power is disconnected from the inductor so output the boost falls to 0V rather than remaining one diode drop below the input voltage.

A µP reset output of MAX8594 clears 20ms (typ) after the COR1 output achieves regulation to ensure an orderly start. In addition,is n the COR1 regulator ot started until the 3.3V main output is in egulation. Also included are a 1% accurate reference and low-battery monitor. Thermal shutdown protects the die from verheating.The AX8594/MAX8594A operate from a 3.1V to a 5.5 supply voltage and consume 46µA no-load supply current. They are packaged in a tiny, 4mm x 4mm, 4-pin thin QFN capable of dissipating 1.67W. The MAX8594 are specified for operation from -40°C to +85°C.